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plaice ... plateau

plaice: (Pleuronectes platessa), commercially valuable European flatfish of the family Pleuronectidae. The plaice, like others of its family, normally has both eyes on the right side of the head. It also ...
Plaid Cymru: political party that has sought self-government for Wales and worked for the protection and promotion of Welsh language, culture, and traditions.
plain: any relatively level area of the Earth's surface exhibiting gentle slopes and small local relief. Plains vary widely in size. The smallest occupy only a few hectares, whereas the largest ...
plain stitch: basic knitting stitch in which each loop is drawn through other loops to the right side of the fabric. The loops form vertical rows, or wales, on the fabric face, ...
plain weave: simplest and most common of the three basic textile weaves. It is made by passing each filling yarn over and under each warp yarn, with each row alternating, producing a ...
Plain, The: in the French Revolution, the deputies of the centre in the National Convention who were the numerical majority. At first, such Plain leaders as Abbe Sieyes and Bertrand Barere backed ...
Plainfield: city, Union county, northern New Jersey, U.S., at the base of the Watchung Mountains. Quakers settled in the area in 1685, and the town became known as Milltown-for its large ...
Plains: city, Sumter county, southwest-central Georgia, U.S., 10 miles (16 km) west-southwest of Americus. A post office was established there in 1839, and when the railroad was built in 1885 several ...
Plains Indian: member of any of the aboriginal North American peoples inhabiting the Great Plains area of the United States and Canada.
plains wanderer: (species Pedionomus torquatus), Australian bird resembling a tiny quail. It has a mottled reddish brown body and a collar of black spots against a white throat. The plains wanderer constitutes ...
plainsong: the Gregorian chant (q.v.) and, by extension, other similar religious chants. The word derives from the 13th-century Latin term cantus planus ("plain song"), referring to the unmeasured rhythm and monophony ...
Plainview: city, seat (1888) of Hale county, northwestern Texas, U.S. It lies on the Llano Estacado, a portion of the High Plains between Amarillo and Lubbock (40 miles [65 km] south). ...
planarian: any of a group of widely distributed, mostly free-living flatworms of the invertebrate class Turbellaria (phylum Platyhelminthes). Planaria is the name of one genus, but the name planarian is used ...
planation surface: any low-relief plain cutting across varied rocks and structures. Among the most common landscapes on Earth, planation surfaces include pediments, pediplains, etchplains, and peneplains. There has been much scientific controversy ...
Planck's constant: (symbol h), fundamental physical constant characteristic of the mathematical formulations of quantum mechanics, which describes the behaviour of particles and waves on the atomic scale, including the particle aspect of ...
Planck's radiation law: a mathematical relationship formulated in 1900 by German physicist Max Planck to explain the spectral-energy distribution of radiation emitted by a blackbody (a hypothetical body that completely absorbs all radiant ...
Planck, Max: theoretical physicist who originated quantum theory, which won him the Nobel Prize for Physics in 1918.
plane: in carpentry, tool made in a wide variety of sizes, used for removing rough surfaces on wood and for reducing it to size. An iron-soled carpenter's plane, found on the ...
plane tree: any of the 10 species of the genus Platanus, the only genus of the family Platanaceae. These large trees are native in North America, eastern Europe, and Asia and are ...
planer: metal-cutting machine in which the workpiece is firmly attached to a horizontal table that moves back and forth under a single-point cutting tool. The tool-holding device is mounted on a ...
planet: (from Greek planetes, "wanderers"), any relatively large natural body that revolves in an orbit around the Sun or around some other star and that is not radiating ...
planetarium: theatre devoted to popular education and entertainment in astronomy and related fields, especially space science, and traditionally constructed with a hemispheric domed ceiling that is used as a screen onto ...
planetary nebula: any of a class of bright nebulae that are expanding shells of luminous gas expelled by dying stars. Observed telescopically, they have a relatively round, compact appearance rather than the ...
planetesimal: one of a class of bodies that are theorized to have coalesced to form Earth and the other planets after condensing from concentrations of diffuse matter early in the history ...
planigale: any of several species of tiny mouselike marsupial animals. See marsupial mouse.
planimeter: mathematical instrument for directly measuring the area bounded by an irregular curve, and hence the value of a definite integral.
plankton: marine and freshwater organisms, which, because they are nonmotile or because they are too small or too weak to swim against the current, exist in a drifting, floating state. The ...
planned parenthood: practice of measures designed to regulate the number and spacing of children within a family.
Planned Parenthood Federation of America: American organization that, since its founding in 1942, has worked as an advocate for education and personal liberties in the areas of birth control, family planning, and reproductive health care.
Planned Parenthood of Southeastern Pennsylvania v. Casey: legal case, decided by the U.S. Supreme Court in 1992, that redefined several provisions regarding abortion rights as established in Roe v. Wade.
Plano: city, Collin and Denton counties, northern Texas, U.S., located about 16 miles (26 km) northeast of Dallas. It is situated in a region of blackland prairie and was first settled ...
planography: any printing technique in which the printing and nonprinting areas of the plate are in a single plane, i.e., at the same level. See offset printing.
Planosol: one of the 30 soil groups in the classification system of the Food and Agriculture Organization (FAO). Planosols are characterized by a subsurface layer of clay accumulation. They occur typically ...
plant: any member of the kingdom Plantae, multicellular, eukaryotic life forms characterized by (1) photosynthetic nutrition, in which chemical energy is produced from water, minerals, and carbon dioxide with the aid ...
plant: (kingdom Plantae), multicellular, eukaryotic life form fundamentally characterized by (1) an almost exclusively photosynthetic mode of nutrition, in which the plant produces chemical energy (in the form of sugars) from ...
plant breeding: application of genetic principles to produce plants that are more useful to humans. This is accomplished by selecting plants found to be economically or aesthetically desirable, first by controlling the ...
plant bug: any member of two families of the insect order Heteroptera. The family Lygaeidae (see lygaeid bug) contains between about 3,000 and 5,000 species. One of the best-known members, the chinch ...
plant development: a multiphasic process in which two distinct forms succeed each other in alternating generations. One form, created by the union of sexual cells (gametes), contains two sets of similar chromosomes ...
plant disease: an impairment of the normal state of a plant that interrupts or modifies its vital functions.
plant hopper: any member of several insect families of the order Homoptera, easily recognized because of the hollow, enlarged head extension that may appear luminous (see lanternfly). Plant hoppers feed on plant ...
plant virus: any of a number of agents that can cause plant disease. Plant viruses are of considerable economic importance because many of them infect crop and ornamental plants. Numerous plant viruses ...
Plantagenet, house of: royal house of England, which reigned from 1154 to 1485 and provided 14 kings, 6 of whom belonged to the cadet houses of Lancaster and York. The royal line descended ...
Plantago: one of three genera in the family Plantaginaceae (order Plantaginales) with about 265 species. The small plants usually have a dense tuft of basal leaves and long, leafless stalks bearing ...
plantain: (Musa paradisiaca), plant of the banana (q.v.) family (Musaceae) closely related to the common banana (M. sapientum). The plantain is a tall plant (3-10 metres [10-33 feet]) with a conical ...
plantain lily: any of about 40 species of hardy herbaceous perennials of the genus Hosta (family Liliaceae). They prefer light shade but will grow under a variety of conditions. They are native ...
plantcutter: any of three species of South American birds of the family Phytotomidae (order Passeriformes), with finely serrated, stout bills used for snipping off tender shoots, buds, and fruit. In some ...
Plante, Francis: French pianist active in Paris in the late 19th century.
Plante, Gaston: French physicist who produced the first electric storage battery, or accumulator, in 1859; in improved form, his invention is widely used in automobiles.
Plante, Jacques: innovative French-Canadian hockey player, one of the most successful of all goaltenders in the National Hockey League (NHL). He was an integral member of the powerful Montreal Canadiens team that ...
Plantin, Christophe: French printer, founder of an important printing house and publisher of the Antwerp Polyglot Bible.
Planudes, Maximus: Greek Orthodox humanities scholar, anthologist, and theological polemicist in the controversy between Byzantium and Rome. His Greek translations of works in classical Latin philosophy and literature and in Arabic mathematics ...
planula: free-swimming or crawling larval type common in many species of the phylum Cnidaria (e.g., jellyfish, corals, and sea anemones). The planula body is more or less cylindrical or egg-shaped and ...
Plasencia: city, Caceres provincia, in the Extremadura comunidad autonoma ("autonomous community"), western Spain. It lies on the Jerte River in the Plasencia valley northeast of Caceres city. Although there are Roman ...
Plaskett, John Stanley: Canadian astronomer remembered for his expert design of instruments and his extensive spectroscopic observations.
plasma: in mineralogy, semitranslucent, microgranular or microfibrous, semiprecious variety of the silica mineral chalcedony. Its colour, various shades of green, is due to disseminated silicate particles of different kinds-e.g., amphibole or ...
plasma: in physics, an electrically conducting medium in which there are roughly equal numbers of positively and negatively charged particles, produced when the atoms in a gas become ionized. It is ...
plasma: in biochemistry, the straw-coloured liquid (including its solutes but excluding the formed elements, such as blood cells and platelets) that constitutes the circulating fluid in animals. Plasma consists of more ...
plasma oscillation: in physics, the organized motion of electrons or ions in a plasma. Each particle in a plasma assumes positions such that the total force resulting from all the particles is ...
plasmapause: portion of the magnetosphere that rotates with the Earth at about four Earth radii (approximately 26,000 km, or 16,000 miles); beyond this region there is a rapid decrease in electron ...
plasmid: in microbiology, an extrachromosomal genetic element that occurs in many bacterial strains. Plasmids are circular deoxyribonucleic acid (DNA) molecules that replicate independently of the bacterial chromosome. They are not essential ...
plasmodesma: microscopic cytoplasmic canals that pass through plant-cell walls and allow direct communication of molecules between adjacent plant cells. Plasmodesmata are formed during cell division, when traces of the endoplasmic reticulum ...
Plasmodiophoromycetes: class of plant parasites in the division Eumycota of the kingdom Mycota (fungi) and referred to as endoparasitic slime molds. Some authors assign them to the kingdom Protista. The class ...
Plasmodium: a genus of parasitic protozoans of the sporozoan subclass Coccidia that are the causative organisms of malaria (q.v.). Plasmodium, which infects red blood cells in mammals (including humans), birds, and ...
Plassey: historic village, east-central West Bengal state, northeastern India. It lies just east of the Bhagirathi River. Plassey was the scene of the decisive victory of British forces under Robert Clive ...
plaster: a pasty composition (as of lime or gypsum, water, and sand) that hardens on drying and is used for coating walls, ceilings, and partitions.
plaster of paris: quick-setting gypsum plaster consisting of a fine, white powder, calcium sulfate hemihydrate (see calcium), which hardens when moistened and allowed to dry. Plaster of paris is prepared by heating calcium ...
plastic: polymeric materials that have the capability of being molded or shaped, usually by the application of heat and pressure. This property of plasticity, often found in combination with other special ...
plastic surgery: surgical specialty concerned with the correction of disfigurement, restoration of impaired function, and improvement of physical appearance. It is largely concerned with the bodily surface and with reconstructive work of ...
plasticity: ability of certain solids to flow or to change shape permanently when subjected to stresses of intermediate magnitude between those producing temporary deformation, or elastic behaviour, and those causing failure ...
Plaszow: Nazi German concentration camp near Krakow, in German-occupied Poland, used chiefly as a forced-labour centre.
Plata, Rio de la: a tapering intrusion of the Atlantic Ocean on the east coast of South America between Uruguay to the north and Argentina to the south. While some geographers regard it as ...
Plataea: ancient city of Boeotia, Greece. It was situated on a triangular ledge 1,000 feet (300 m) above sea level, on the northern side of Mount Cithaeron below the modern village ...
plate glass: form of glass originally made by casting and rolling and characterized by its excellent surface produced by grinding and polishing. Plate glass was first made in the 17th century in ...
plate tectonics: theory dealing with the dynamics of the Earth's outer shell, the lithosphere. According to the theory, the lithosphere consists of about a dozen large plates and several small ones. These ...
platea: in medieval theatre, the neutral acting area of a stage. In medieval staging, a number of mansions, or booths, representing specific locations, were placed around the acting area. The actors ...
plateau: extensive area of flat upland usually bounded by an escarpment on all sides but sometimes enclosed by mountains. The essential criteria for plateaus are low relative relief and some altitude. ...