General Information (I-P)
General Information (I-P)
Igneous rock is rock formed from cooling lava.
Impalement is a method of execution carried out by thrusting a stake through the body.
The inch is a unit of the imperial scale of measurement of the length equivalent to 25.4 millimeters.
Income Tax is a tax levied directly from income of every description. It was first levied in Britain in January 1799, then repealed in 1802 and reinstated the same year under the name of Property Tax. It was fixed at 10% in 1806 and repealed in 1816 only to be reinstated in 1842. Since then the rate has fluctuated with the political whims of the current ruling party, and it is currently graduated but starting at 20%.
The Indian ocean is the sea separating Africa from Australia. It has a total area of 73,600,000 km2
Indium is a soft, rare metal element.
An interface is a shared boundary between two devices. These may be a human and a machine for example. Computer operating systems use an interface to receive and transmit data to and from a human operator.
Interlisp is a dialect of the Lisp programming language. It is a computer programming language designed for procedure orientated representation. It has all the standard features of Lisp, plus extensive debugging facilities, and a DWIM self-correcting facility.
Interpol is an international police organisation with headquarters in Paris.
Invisible describes something that cannot be seen.
Iodine is a non-metal element.
An ion is a charged atom or group of atoms.
Irradiation is the process of exposing something to radiation. It is used to preserve food and destroy cancer growths.
Irrigation is the process of supplying water to land through a series of artificial waterways.
An isotope is a form of an element which has a different atomic weight and nuclear properties than other isotopes of the same element.
Jah is the Jamaican, and more especially the Rastafarian, name for god.
The Jansky is the unit of radiation received from outer space, used in radio astronomy. It is equal to 10-26 watts per square meter per hertz, and is named after the USA engineer Karl Jansky.
Judo is a form of Japanese wrestling.
Judy is an English slang expression for a woman.
Jujitsu is a Japanese form of self defence.
The Jurassic was the tenth geological period, 135,000,000 years ago. The first mammals evolved.
Jute is a fibre obtained from plants and used for making sacks.
The kayser is the unit of wave number (number of waves in a unit length), used in spectroscopy. It is expressed as waves per centimeter, and is the reciprocal of the wavelength. A wavelength of 0.1 cm has a wave number of 10 kaysers.
Keratin is a fibrous protein.
A kid is a baby goat.
Historically, a knight was an honourable military rank which was bestowed upon a noble who had served as a page and squire by the king. Today a knight is a social title bestowed upon people for supposed service to the crown or country, and entitles them to be called "Sir" rather than "Mister".
Knighthood is the social rank of knight.
In navigation the knot is the unit by which a ship's speed is measured, equivalent to one nautical mile per hour (one knot equals about 1.15 miles per hour). It is also sometimes used in aviation.
Knowledge is practical understanding.
Kohl is antimony sulphide used by women as eye make up.
The koto is a stringed musical instrument from Japan.
Kung Fu is a form of Chinese unarmed combat.
A labret is an ornament inserted in a hole pierced through the lip.
A labyrinth is a maze like structure.
Lachrymation is the anatomical term for the shedding of tears.
Lacrosse is a ball-game originally played by North American Indians with twelve players on each side, in which the ball is flung by and carried in the crosse, the object being to throw the ball through the opponents' goal.
Lactic acid is an organic acid formed by certain bacteria during fermentation. It also occurs in the muscles when they are exercised vigorously. It is used in food preservation and pharmaceuticals.
Lactose is a sugar found in solution in milk. It is the combination of glucose and galactose.
Ladanum is a gum resin extracted from plants of the genus Cistus and used in perfume.
Ladino is a Spanish dialect spoken by Sephardic Jews.
A lagoon is a shallow stretch of salt water partly or wholly separated from the sea by a narrow strip of land or a low sand-bank or coral reef.
Lallans is a Lowland Scottish language.
A lamb is a young sheep.
Lambda is the 12th letter of the Greek alphabet.
The lambert is the unit of luminance (the light shining from a surface), equal to one lumen per square centimeter. In scientific work the candela per square meter is preferred.
Lambrequin was originally a material covering worn over a helmet. It is now a term applied to a short piece of drapery hung over the top of a door or window.
A lamella is a thin plate, scale or film of bone or tissue.
The lamina is the blade on the leaf on either side of the midrib on flowering plants. It is usually the primary organ of photosynthesis.
A lamp is a vessel filled with oil and fitted with a wick which is then used to provide light. The term has come to apply to any device which provides illumination, including electric lamps.
Lampas is a horse disease with a swelling in the roof of the mouth.
A Lancastrian is an inhabitant of Lancashire.
A lancet is a fine pointed, double-edged surgical knife.
A landau is a four-wheeled carriage with a top, the back and front of the top can be raised and lowered independantly of each other.
Landscape is a term applied to inland scenery, or a picture of inland scenery.
A lane is a narrow road, usually between hedges, or a passage way.
Lanolin is a wax derived from sheep's wool.
The lanthanides are a group of 15 elements.
A lanyard is a cord attached to a knife or whistle with which to hold it, or to serve as a handle.
A laparotomy is a surgical incision through the abdominal walls into the abdominal cavity.
A lapel is a part of the front of a coat which is folded back towards the shoulder.
Lard is the rendered and clarified internal fat from the abdomen of pigs or cattle used in cooking and pharmacy.
A larder is a room or cupboard used for storing provisions.
A lardon is a strip of bacon or pork used to lard meat.
Laser is an acronym for Light amplification by stimulated emission of radiation. It is a device producing an intense narrow beam of light.
Lassa fever is an incurable fever caused by a virus carried by a species of rat found in west Africa.
A lasso is a rope with a running noose used for catching cattle.
A latchet was a thong used for fastening a shoe.
A lath is a thin narrow strip of wood. Laths are used for supporting plaster, and to construct trellis.
A lathe is a machine used for turning wood, metal and other materials by rotating the article against tools which cut it to shape.
Latin is an Indo-European language which originated amongst the people of ancient Latium and the Romans.
Latten is a yellow alloy of copper, zinc, lead and tin used for making monumental brasses and church candlesticks.
A lattice is a framework of laths crossed diagonally so as to form a net-like structure to be used as a screen or door.
Laudanum is a tincture of opium.
Lava is the molten material expelled by a volcano. It cools to form igneous rock.
A laxative is a substance which loosens the bowels assisting or encouraging the excretion of faeces.
A lazaret is a hospital for the poor, especially for lepers.
Lead is a soft, malleable, metalic element. It occurs in many ores, the most important of which is galena. It is a very dense metal, and is used as a shield in environments where radiation abounds, such as X-Rays and the nuclear industry.
In botanical terms, a leaflet is a division of a compound leaf.
A league was a measurement of distance, it was equivalent to roughly 3 miles or just under 5 km.
Leather is a material prepared from the hides of dead animals.
Lebensraum was the theory of living space used by the Nazis to justify their annexation of neighbouring states on the grounds that Germany was overpopulated during the 1930s.
Leeward is a nautical expression, refering to the opposite side of the ship to that from which the wind is blowing.
A legacy is a sum of money or article bequeathed by will and handed down from a predecessor.
Leo is a sign of the zodiac represented by a lion.
Leprosy is a disease of the skin characterized by the formation of nodules or tubercles in the skin. There are variations, one causes the loss of bones which results in mutilation of the limbs.
Libra is a sign of the zodiac represented by a set of scales.
Light is electromagnetic radiation detectable by the eye.
The link is a unit of the imperial scale of measurement of length equivalent to 7.92 inches.
A lipid is an organic substance that is soluble in solvents such as alcohol but not in water.
A liqueur is a strong sweet alcoholic beverage with a spirit base and flavoured with aromatics.
Lithography is a printing process invented by Senefelder in 1796.
Litmus is a dye derived from lichens and used to test acidity.
Logo is a computer programming language designed to teach mathematical concepts. It was developed in the early 1970s in America.
Lysergic acid diethylamide (lsd) is an hallucinogen illegal drug.
Lumbago is pain in the lower part of the back.
The lute is a family of stringed musical instruments that were in use during the 14th to 18th centuries.
The lux is the SI unit of illuminance or illumination (the light falling on an object). It is equivalent to one lumen per square meter or to the illuminance of a surface one meter distant from a point source of one candela.
Magnesium is a metal element that burns with a very bright white light.
Magnesium oxide is formed when magnesium is burnt in the air. It is a white powder that is used to treat acidity in the stomach.
Mal de mer is French for sea sickness.
Malaria is an intermittent and remittent fever caused by the micro-organism Pasmodium and transmitted by the bite of the Anopheles mosquitoe.
Malayalam is a Dravidian dialect closely related to Tamil and widely spoken on the west coast of south India.
Something which is malleable can be hammered into a new shape with out fracturing or returning to its original shape.
A mallet is a large and heavy hammer, usually made of wood.
Malt is derived from grain, usually barley, which is steeped in water and made to germinate which causes the grain's stach to convert into saccharine matter, it is then dried in a kiln and used in the brewing of beer, distilling of whisky and other culinary uses.
Maltose is a sugar formed naturally from starch during the germination of grain. It is two glucose molecules combined.
The mandolin is a stringed musical instrument descended from the lute.
Manx is a dialect of gaelic once spoken in the Isle Of Man.
In physics, mass is the quantity of matter which a body contains.
The maund was a unit of measurement used in India around 1900. It is equivalent to 40 seer.
The maxwell is the c.g.s. unit of magnetic flux. It is now replaced by the SI unit, the weber (one maxwell equals 10-8 weber). The maxwell is a very small unit, representing a single line of magnetic flux. It is equal to the flux through one square centimeter normal to a magnetic field with an intensity of one gauss.
A maze is a confusing network of passages and winding interconnecting paths.
Mead is an alcoholic beverage made from fermented honey.
Meliorism is the doctrine that the world may be made better by human effort.
A melodeon is a type of accordion.
Melody is the tune of a piece of music.
A menorah is a seven-branched candelabrum used in jewish worship.
Menthol is an alcohol derivative of menthone and occurs in peppermint.
Mercury fulminate is an explosive used in detonators and percussion caps.
Metal is a class of elements.
A meteor is a small solid body which sails through space.
A meteorite is a piece of rock or metal from space.
Methane is the simplest hydrocarbon. It is an odourless gas that is explosive when mixed with oxygen.
Methanoic acid is a fuming liquid that occurs in stinging nettles.
Methanol is the simplest alcohol having the formulae ch3oh.
Methodism is a religious movement. It was founded by John Wesley, Charles Wesley and George Whitfield in reaction to apathy within the Church of England.
Mezzotint is a method of engraving on copper or steel.
A micrometer is an instrument for measuring minute lengths or angles with great accuracy; different types of micrometer are used in astronomical and engineering work.
The type of micrometer used in astronomy consists of two fine wires, one fixed and the other movable, placed in the focal plane of a telescope; the movable wire is fixed on a sliding plate and can be positioned parallel to the other until the object appears between the wires.
The movement is then indicated by a scale on the adjusting screw.
The micrometer caliper, of great value in engineering, has its adjustment effected by an extremely accurate fine-pitch screw (vernier).
A microphone is the first component in a sound recording system. It converts sound waves into electrical energy. A simple microphone is the telephone receiver mouthpiece.
A microtome is an instrument used for cutting very thin sections of organic tissue for microscopic examination.
Mildew is a growth of minute fungi.
The mile is a unit of the imperial scale of measurement of length equivalent to 8 furlongs, 1760 yards or 1.6093 kilometres.
Millennium is a period of measurement being 1000 years.
A mineral is an element or compound occuring naturally due to inorganic processes.
Ming is the name of the Chinese dynasty which ruled from 1368 to 1644.
The Miocene was the sixteenth geological period, 25,000,000 years ago. The first apes evolved.
A mizzen is the fore and aft sail on the after side of the mizzen-mast of a three-masted ship.
Modem is a contraction of the term Modulator/Demodulator. It is a device that modulates and demodulates signals on and off a "carrier" frequency. It is not limited to computer data use, thus the telco-specific term "data set" for data modems.
Modulation is alterations in the characteristics of analog carrier waves, impressed on the amplitude, phase and/or the frequency of the wave.
A molecule is the smallest particle of any substance that can exist and still exhibit the properties of the substance.
Monday is the first day of the week.
Monosaccharide is a simple carbohydrate.
The month is a unit of measurement of time based upon the motion of the moon around the earth.
The moon is the natural satellite of the earth. It is 3476 km in diameter and has a mass 1/8th that of the earth. It orbits the earth every 27.32 days.
Moreen is a fabric made from wool or wool and cotton in imitation of moire.
The morel is a genus of edible mushrooms.
Moroxite is the crystallized form of apatite, occuring in crystals of a brownish or greenish-blue colour.
Morphine is an opium alkaloid used to treat severe pain.
Mountaineering is the practice of climbing mountains.
Mean Time Between Failure (MTBF) is a statistical method developed and administered by the U.S. military for purposes of estimating maintenance levels required by various devices and systems. Since accurate statistics require a basis of "failures per million hours of operation," an MTBF estimate on a single device is not very accurate; it would take 114 years to see if the device really had that many failures! Similarly, since the MTBF is an estimate of averages, half of the devices can be expected to fail before then, and half after. MTBF cannot be used as a guarantee. Telecommunications systems operate on the principle of "Availability," for which there is a body of CCITT Recommendations.
A muffle is an arched fire-brick furnace used in assaying operations.
Mullagatawny is a soup made with meat cut into small pieces and mixed with rice and curry-powder.
Multileaving is an IBM Bisync-era method of interspersing message blocks for various applications on a single line.
Mum is a malt liquor made of malt wheat, oats and bean meal. It was brewed extensively in Brunswick at the start of the 20th century.
A mummy is any dead body, human or animal, that has been naturally or artificially preserved. Natural mummification can occur through freezing, drying, or preservation in bogs or oil seeps. Artificial mummification may be achieved by embalming (for example, the mummies of ancient Egypt) or by freeze-drying.
Mumps is an infectious disease which attacks the young and consists of a painful inflammation of the salivary glands with swelling along the neck.
Mungo is a material similar to shoddy which is made from old woollen fabrics which have been torn up for remaking.
Munjeet is a dye obtained from the roots of the Rubia cordifolia plant which is grown in India.
Muriatic Acid was a former name for Hydrochloric acid.
Murrine vases were priceless vessels brought from Carmania in Perisa and used in ancient Rome as winecups where it was believed they would break if poison was mixed with the wine.
Musk is a substance used in perfume and obtained from the Musk-deer. Musk is also used in medicine as an antispasmodic.
Muslin is a fine thin cotton fabric first imported into England in 1670 from India.
Myckle ail is the old English name for leprosy.
Myrrh is a gum resin produced by a tree found in Arabia. It is used as incense and in embalming.
Myxoedema is a thyroid deficiency.
Nack (nak) is the "Negative Acknowledge" character in many data codes; typically used to indicate receipt of a corrupted message, ordering retransmission.
The nail is a unit of the imperial measurement of length equivalent to 1/16 yards.
The Napoleonic wars were a series of European wars between 1803 and 1815 involving Napoleon and his conquests of Europe.
A narcotic is a sleep inducing and analgesic drug.
NASA (National Aeronautics and Space Administration) is an American government agency founded in 1958 for spadeflight and aeronautical research. Its headquarters are in Washington DC. Its main installation is the Kennedy Space Center.
The Nautical Mile is a unit of measurement used by ships. It is 1852 meters long.
A nebula is a cloud of gas and dust in space.
Neptunium is an artificial element produced in nuclear reactors.
Neuralgia is a pain originating from the nerves.
Neurosis is a mild mental condition of emotional disorders.
Neurosurgery is surgery upon the brain or spinal cord.
The neutron is a subatomic particle.
A newspaper is a publication reporting and commenting upon news. The first newspapers were published by the Romans.
Nickel Silver (German Silver, Pack-Fong) is an alloy of copper, nickel and zinc in different proportions. Sometimes lead is added if the alloy is destined for making candlesticks or casts.
Nicotine is an alkaloid derived from the leaves of tobacco.
Niello is a black, metal, amalgam of sulphur added to copper, silver or lead and used for filling engraved lines in metal objects.
Nimbostratus is a type of cloud, low, dark grey and trailing.
A nimbus is a bright cloud or halo added to pictures of saints etc implying deity.
A nitrate is any salt of nitric acid.
Nitrazepam is a hypnotic drug given by mouth to treat insomnia.
Nitrogen is a gaseous element. It comprises 79 percent of the air.
Nitroglycerine is a powerful explosive produced from nitric acid and glycerol.
Nocardiosis is a disease affecting the skin, lungs and brain resulting in abscesses.
A noose is a loop with a running knot which tigthens as the string is pulled.
The term norse refers to ancient Norway.
A nova is a faint star that suddenly erupts in brightness.
Nucleic acid is a complex organic acid forming the basis of heredity.
The nucleus is the positively charged central part of an atom.
Numismatics is the study of coins and medals.
Nylon is a synthetic plastic similar in chemical structure to protein.
Obeah is a form of witchcraft practised in the Caribbean.
The oboe is a musical instrument of the woodwind family.
Obsidian is volcanic glass.
The ohm is the SI unit of electrical resistance. It was originally defined with reference to the resistance of a column of mercury, but is now taken as the resistance between two points when a potential difference of one volt between them produces a current of one ampere.
Ohm's law is that the steady current in a metal circuit is directly proportional to the constant total electromotiveforce in the circuit, that is e/i = r
Oil is a large group of viscid liquids which have a characteristic smooth and sticky feel, are lighter than water, are inflammable and chemically neutral.
The Oligocene was the fifteenth geological period, 42,000,000 years ago.
Opera is a stage entertainment consisting of a play sung to music in its entirety, with no spoken dialogue at all. Opera originated in Italy around 1600 and has subsequently spread throughout the world.
Opium is a drug extracted from the seeds of the opium poppy.
The Ordovician period was the fourth geological period, 375,000,000 years ago.
In chemistry, the term organic refers to substances which occur naturally as constituents of organized bodies.
Origami is the art of paper folding.
The ounce is a unit of measurement of the avoirdupois scale equivalent to 16 drams or 28.350 grams.
Oxidation is the chemical combination of atoms with oxygen atoms to form oxides. In metals, the process appears as rust, iron rust being iron oxide, a molecule formed of iron atoms combined with oxygen atoms.
The term oxidize refers to the chemical reaction of oxidation.
Oxygen is a gaseous element that is partly soluble in water. It is the only gas able to sustain respiration.
Oxytocin is a hormone that stimulates the uterus in late pregnancy to initiate and sustain labour.
Ozone is a blue gas. The molecules are comprised of three oxygen atoms.
A pacemaker is an electronic device that stimulates the heart muscles by delivery small electric shocks to it.
In the sense of communications, a packet is a structured group of binary digits in a prearranged sequence containing synchronism, address, control an error-checking data. Specialized synonym for a "block" of data in CCITT Packet Data Network standards.
A Packet Switched Network is a network dedicated to the routing and delivery of data put in the form of standardized "packets."
Packet Switching is the technique in which a stream of data is broken into standardized units called "packets," each of which contains address, sequence, control, size and error checking information in addition to the user data. Specialized packet switches operate on this added information to move the packets to their destination in the proper sequence and again present them in a contiguous stream.
The Paleocene wa the thirteenth geological period, 80,000,000 years ago.
A pancratium is an athletic contest in wrestling and boxing.
Paracetamol is an analgesic. Over doses of paracetamol can cause liver damage.
Paraffin is a family of hydrocarbons.
The term parallax describes the apparent movement of an object when viewed from two different positions.
Parallel Transmission is the simultaneous transmission of all parts of a signal at one time; in data transmission, requiring a separate signal path for each of the bits of a character; internal to computers, this is called a "parallel bus."
Parchment is a type of fine writing paper traditionally made from sheep or goat skin.
In communications systems and computers, parity is a constant state of equality; one of the oldest and simplest methods of error checking data transmission. Characters are forced into parity (total number of marking bits odd or even as selected by choice) by adding a one or zero bit as appropriate when transmitted; parity is then checked as odd or even at the receiver.
A Parity Bit is a check bit appended to an array of binary digits to make the sum of all the digits always odd or always even.
Parity Check is a checking method that determines if the sum of all the digits in an array is odd or even.
A parsec is an astronomical unit of distance equivalent to 3.2616 light years.
Pasteurization is a preservative heat treatment applied to foods, notably milk.
PDS is an abbreviation for Portable Diagnostic System. It is an expert system which diagnoses faults in machinery from information received from sensors connected to the machinery. Sensor readings are compared with known data about component malfunction symptoms to diagnose faults.
Peat is a fibrous organic compound found in bogs that is formed by the partial decomposition of plants.
The peck is a unit of capacity measurement equivalent to 2 gallons or 9.092 litres.
A pentagon is a five sided regular polygon.
The pentathlon is a five sport competition.
A pentode is an electronic amplifying valve with 5 main electrodes.
A pentose is a sugar with 5 carvon atoms in the molecule.
A penumbra is a partly shaded region around the shadow of an opaque body. The term is especially applied to describe the partly shaded region around a total eclipse of the sun or moon.
Perception is the ability to observe and understand, particuarly intuitively.
A percolator is a device for making coffee by allowing water to filter repeatedly through ground coffee.
The pericarp is the wall of the ripened ovary of a plant.
Perigee is an astronomical term refering to the position in the Moon's orbit nearest to the earth, opposite to Apogee.
A perigynous plant is one which has stamens situated around the pistil or ovary.
Permafrost is the permanently frozen subsoil in Arctic regions.
Permaid is an expert system, developed at Honeywell for trouble shooting large disk drives.
Permalloy is a nickel steel alloy, containing about 78 percent nickel. It is charcterized by a very high permeability in low magnetic fields. It is extensively used in submarine cables.
A permanganate is any salt of permanganic acid.
The permian was the eigth geological peiod, 205,000,000 years ago. It marked the evolution of the reptiles.
The persimmon is a yellow-orange plum-like astringent fruit. It becomes sweet when softened by frost.
Phencyclidine is an illegal drug also known as angel dust.
Phenol is a compound derived from coal tar and used in the manufacture of nylon.
A phosphate is any salt of phosphorus oxy acids.
Phosphorus is a non-metallic element.
Photosynthesis is the process by which plants convert carbon dioxide into carbohydrates by chlorophyll under the influence of light.
The piano is a musical instrument with a keyboard. It was invented in the 18th century as a development of the harpsichord. Strings are stuck by hammers when the keys are depressed.
Pica is a size of print (12 point) giving about 6 lines to the inch.
A picador is a horse-mounted, lance armed bull fighter.
A picaroon was a name for pirate or pirate ship.
The piccolo is a woodwind instrument of the flute family.
Pilau is an oriental dish of rice with meat or fish and spices.
Pinchbeck is an alloy of 80% copper and 20% zinc once used for making cheap watch cases, and more recently as a substitute for the more expensive bronze. It was invented by a London watchmaker in the 18th century.
The pint is a unit of capacity measurement equivalent to 4 gills or 0.568 litres.
Pitch is the highness or lowness of a musical sound.
A piton is a metal spike used in mountaineering as a support for a belaying pin.
A pitpan is a Central American dug-out boat.
A planet is a heavenly body which orbits a star.
A Planimeter is a simple integrating instrument for measuring the area of a regular or irregular plane surface. It consists of two hinged arms: one is kept fixed and the other is traced around the boundary of the area. This actuates a small graduated wheel; the area is calculated from the wheel's change in position.
A plant is a living organism of the vegetable kingdom. Generally they are capable of living wholly on inorganic substances. They lack locomotion and special organs of sensation and digestion.
A plantation is a an assemblage of planted and growing plants.
Plaster of paris is calcium sulphate mixed with water to make casts.
Plastic is a group of synthetic polymers made from oils and which are capable of being moulded into shape by heat or pressure or both.
The Pleistocene (ice age) was the seventeenth geological period, 500,000 years ago. It marked the evolution of tool-making man.
The Pliocene was the sixteenth geological period, 8,000,000 years ago. It marked the modern formation of the continents.
A plough is an agricultural implement used for tilling the soil.
Pneumonia is an inflammation of the lung due to infection.
Polio is a virus infection of the central nervous system affecting nerves that activate muscles.
The polka is a lively folk dance.
Polyester is a thermosetting plastic used in the manufacture of synthetic fabrics.
Polyethylene is a thermosetting plastic polymer of ethylene.
A polymer is a compound made up of large molecules composed of many repeated simple units.
Polypus is a small benign tumour of the skin due to local overgrowth of the celss.
A polysaccharide is a long chain of carbohydrate made up of hundreds of linked simple sugars, such as glucose.
The poor laws were an act of parliament between 1562 and 1601 which gave local authorities the responsibility for settling and supporting the poor in England.
The poundal is the imperial unit of force, now replaced in the SI system by the newton. One poundal equals 0.1383 newtons. It is defined as the force necessary to accelerate a mass of one pound by one foot per second per second.
Praseodymium is a metal element used as a pigment in glass.
The Pre-Cambrian period was the second geological period. It was the time when the first animal life appeared, about 1,125,000,000 years ago.
Presto is a musical term designating a faster rate of movement than that indicated by allegro.
Prolog is a computer programming language used mainly for artificial intelligence.
Propaganda was an association established in Rome in 1622 for the purpose of diffusing a knowledge of Roman Catholicsim throughout the world.
Propylaea is an architectural term refering to the entrance to a Greek temple.
Protein is a long chain molecule made up of amino acids joined by peptide bonds. Protein forms the structural material of bodily tissues.
A proton is a positively charged sub atomic particle.
Psychoanalysis is a theory and treatment method for neuroses developed by Freud.
Psychology was originally thought of as a department of philosophy which dealt with the mind. Today, it is recognised as the science of the nature, function and phenomena of the human mind and human behaviour.
A pub is a house licensed for the sale and consumption of alcoholic beverages.
A pump is a machine for moving fluid from one place to another.
Pumpernickel is a German wholemeal rye bread. It is dark brown and often sweetened and spiced.
A punch is a machine for making or starting holes.
Purple is a secondary colour compounded by the union of the primaries blue and red. As a dye it was originaly obtained from Tyrian dye.
Pus is a yellowish liquid that forms in the body as a result of bacterial infection.
In billiards, pyramids is a game played with 15 red balls and 1 white ball. The red balls are placed together in the shape of a triangle, or pyramid at the spot. The object of the game being to pot the most balls. This game was popular around 1900, and may perhaps have developed into the modern game of Pool.
Pyrogallic Acid (pyrogallol) is an acid obtained by the dry distillation of gallic acid. It forms colourless, odourless crystals, is readily soluble in water, alcohol and ether and its alkaline solution readily absorbs oxygen. It is used as a developer in photography.
A pyrometer is a device for measuring temperatures outside of the range of a mercurial thermometer.
A pyrophone is a musical instrument, in which the various notes are produced by the burning of hydrogen gas within glass tubes of varying lengths and sizes.
The Pyrrhic Dance was an ancient Greek dance which consisted of moves representing an attempt to avoid the strokes of an enemy in battle. It was viewed as a kind of training for war.
A pyx was a covered vessel used in the Roman Catholic church to contain the consecrated host. In ancient times it was sometimes made in the shape of a dove.
In botany, a pyxidium is a capsule with a lid, as seen in the henbane and in the fruit of the monkey-pot tree.