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cat shark ... category

cat shark: (family Scyliorhinidae), any of more than 80 species of small, mottled sharks (order Lamniformes). Although many bottom-dwelling species are rare and poorly known ecologically, representatives have been found in all major marine environments of the tropical and temperate regions. Most ...
cat snake: (genus Telescopus), any of about 15 species belonging to the family Colubridae. Cat snakes have vertical pupils, like a cat, and are nocturnal, preying chiefly on lizards.
cat's-eye: any of several gemstones that, when cut en cabochon (in convex form, highly polished), display a luminous band reminiscent of the eye of a cat; this particular quality is termed chatoyancy. Precious, or oriental, cat's-eye, the rarest and most highly ...
cat, domestic: (species Felis catus), domesticated member of the family Felidae, order Carnivora. Like all felids, domestic cats, the smallest members of the family, are characterized by supple, low-slung bodies, finely molded heads, long tails that aid in balance, ...
catabolism: the sequences of enzyme-catalyzed reactions by which relatively large molecules in living cells are broken down, or degraded. Part of the chemical energy released during catabolic processes is conserved in the form of energy-rich compounds (e.g., adenosine triphosphate [ATP]).
cataclastite: any rock produced by dynamic metamorphism during which faulting, granulation, and flowage may occur in previously crystalline parent rocks. When stress exceeds breaking strength, a rock yields by rupture. The rock may break as a unit, or individual minerals may ...
catacomb: subterranean cemetery composed of galleries or passages with side recesses for tombs. The term, of unknown origin, seems to have been applied first to the subterranean cemetery under the Basilica of San Sebastiano (located on the Appian Way near Rome), ...
catafalque: ornate, often theatrical, usually movable funereal structure mounted on a stage to support a coffin for a lying-in-state. It is used for royalty and personages of distinction and is normally set up in a historic public hall, such as Westminster ...
Catalan language: Romance language spoken in eastern and northeastern Spain, chiefly in Catalonia and Valencia. It is also spoken in the Roussillon region of France, in Andorra, and in the Balearic Isles. The official language of the kingdom of Aragon in the ...
Catalan literature: the body of literature written in the Catalan language, prominent from the 13th to the 16th century and then revived in the 19th and 20th centuries.
catalase: an enzyme that brings about (catalyzes) the reaction by which hydrogen peroxide is decomposed to water and oxygen. Found extensively in mammalian tissues, catalase prevents the accumulation of and protects the body tissues from damage by peroxide, which is continuously ...
catalexis and acatalexis: in prosody, an omission or incompleteness in the last foot of a line or other unit in metrical verse and, conversely, the metrical completeness of such a unit.
Catalhuyuk: major Neolithic site in the Middle East, located near Konya in south-central Turkey. Excavations (1961-65) by the British archaeologist James Mellaart have shown that Anatolia in Neolithic times was the centre of an advanced culture. The earliest building period at ...
catalog verse: verse that presents a list of people, objects, or abstract qualities. Such verse exists in almost all literatures and is of ancient origin. The genealogical lists in the Bible and the lists of heroes in epics such as Homer's Iliad ...
Catalonia: comunidad autonoma ("autonomous community") and historic region of Spain, encompassing the northeastern Spanish provincias of Girona (Gerona), Barcelona, Tarragona, and Lleida (Lerida) and established by the statute of autonomy of Dec. 18, 1979. The autonomous community of Catalonia, which has ...
Catalonia Museum of Art: museum in the Palacio Nacional in Barcelona, housing one of the most important collections of medieval paintings in the world and also a fine and complete collection of Spanish ceramics. The Romanesque Galleries comprise a series of reconstructions of church ...
catalpa: any of 11 species of trees in the genus Catalpa (family Bignoniaceae), native to eastern Asia, eastern North America, and the West Indies. Catalpas have large, attractive leaves and showy, white, yellowish, or purplish flowers. The catalpa fruit is a ...
catalufa: any of certain fishes of the bigeye (q.v.) group.
catalysis: in chemistry, the modification of the rate of a chemical reaction, usually an acceleration, by addition of a substance not consumed during the reaction.
catalyst: in chemistry, any substance that increases the rate of a reaction without itself being consumed. Enzymes are naturally occurring catalysts responsible for many essential biochemical reactions.
catalyst poison: substance that reduces the effectiveness of a catalyst in a chemical reaction. In theory, because catalysts are not consumed in chemical reactions, they can be used repeatedly over an indefinite period of time. In practice, however, poisons, which come from ...
catamaran: twin-hulled sailing and powered boat developed for sport and recreation in the second half of the 20th century. Its design is based on a raft of two logs bridged by planks that had earlier been used by peoples in the ...
Catamarca: city, capital of Catamarca provincia (province), northwestern Argentina, on the Rio del Valle de Catamarca, a river between the two south-pointing spurs of the Andean peaks of Ambato and Ancasti. Originally named Londres, it was founded by ...
Catamarca: provincia (province), northwestern Argentina, separated from Chile by the Andes Mountains. The province is generally mountainous with intermontane tablelands and valleys (some fertile, others completely arid). The sandy desert on the west side of the Aconquija Mountains ...
Catanduanes: island, east-central Philippines, in the Philippine Sea, separated from southeastern Luzon (Rungus Point) by the shallow Maqueda Channel. Farming is diversified (rice, corn [maize], copra, abaca) on the hilly, rolling land. Virac, the chief port, is on the southern coast ...
Catanduva: city, in the highlands of north-central Sao Paulo estado (state) Brazil, on the Sao Domingos River at 1,630 feet (497 metres) above sea level. Originally called Vila Adolfo, the settlement was given town status in 1909 and ...
Catania: city, eastern Sicily, Italy, in the broad plain of Catania on the Ionian seacoast, south of Mount Etna. The city was founded in 729 BC by Chalcidians (settlers from Chalcis in the Greek island of Euboea) from Naxos, 50 miles ...
Catania, Gulf of: inlet of the Ionian Sea on the eastern coast of Sicily. About 20 miles (32 km) long and 5 miles (8 km) wide, it lies between Cape Campolato (south) and Cape Molini (north). The gulf receives the Simeto River below ...
Catanzaro: city, capital of Calabria regione (region), southern Italy, at an elevation of 1,125 feet (343 metres) overlooking the Gulf of Squillace, southeast of Cosenza. Founded about the 10th century as Catasarion, a Byzantine town, it was taken ...
catapult: mechanism for forcefully propelling stones, spears, or other projectiles, in use since ancient times. The Romans used the word ballista to designate an engine used to hurl stones and catapulta for one that shot arrows and darts, although the larger ...
cataract: a waterfall (q.v.), especially one containing great volumes of water rushing over a precipice.
cataract: in medicine, opacity of the crystalline lens of the eye. If the opaque areas are minute, scattered dots (a condition known as blue dot cataract, or punctate cataract) or if only the periphery of the lens is affected (this type, ...
Catargiu, Lascar: Romanian statesman, four times prime minister (1866, 1871-76, 1889, 1891-95), who played a leading role in national affairs through the country's early years of independence.
catastasis: the dramatic complication that immediately precedes the climax of a play or that occurs during the climax of a play. Compare catastrophe.
catastrophe: in literature, the final action that completes the unraveling of the plot in a play, especially in a tragedy. Catastrophe is a synonym of denouement. The term is sometimes applied to a similar action in a novel or story.
catastrophe theory: in mathematics, a set of methods used to study and classify the ways in which a system can undergo sudden large changes in behaviour as one or more of the variables that control it are changed continuously. Catastrophe theory is ...
catastrophism: doctrine that explains the differences in fossil forms encountered in successive stratigraphic levels as being the product of repeated cataclysmic occurrences and repeated new creations. This doctrine generally is associated with the great French naturalist Baron Georges Cuvier (1769-1832). One ...
Catatumbo River: river rising in northern Colombia. It flows northeast across the Venezuelan border, crosses rich oil-bearing regions in the Maracaibo Lowland, and empties into Lake Maracaibo after a course of about 210 miles (338 km). It is navigable in its lower ...
Catawba: North American Indian tribe of Siouan language stock who inhabited the territory around the Catawba River in the Carolinas. Their principal village was on the west side of the river in what is now York county, S.C. They were known ...
catbird: any of several bird species named for their mewing calls, which are used in addition to song. The North American catbird (Dumetella carolinensis), of the family Mimidae (order Passeriformes), is 23 cm (9 inches) long and is gray, with a ...
catch: perpetual canon designed to be sung by three or more voices, especially popular in 17th- and 18th-century England. Like all rounds, catches are indefinitely repeatable pieces in which all voices begin the same melody on the same pitch but enter ...
catch-as-catch-can wrestling: basic wrestling style in which nearly all holds and tactics are permitted in both upright and ground wrestling. Rules usually forbid only actions that may injure an opponent, such as strangling, kicking, gouging, and hitting with a closed fist. The ...
Cateau-Cambresis, Peace of: (April 3, 1559), agreement marking the end of the 65-year (1494-1559) struggle between France and Spain for the control of Italy, leaving Habsburg Spain the dominant power there for the next 150 years. In the last phase of the war, ...
catechetical school: in early Christianity, a type of educational institution with a curriculum directed toward inquirers (especially those trained in the Greek paideia, or educational system) whose aim was to gain a greater knowledge of Christianity and eventually, perhaps, baptism into the ...
catechism: a manual of religious instruction usually arranged in the form of questions and answers used to instruct the young, to win converts, and to testify to the faith. Although many religions give instruction in the faith by means of oral ...
catecholamine: any of various naturally occurring amines that function as neurotransmitters and hormones within the body. Catecholamines are characterized by a catechol group (a benzene ring with two hydroxyl groups) to which is attached an amine (nitrogen-containing) group. Among the catecholamines ...
catechumen: a person who receives instruction in the Christian religion in order to be baptized. According to the New Testament, the apostles instructed converts after baptism (Acts 2:41-42), and Christian instruction was evidently given to all converts (Luke 1:4, Acts 18:25, ...
Catechumens, Liturgy of the: the instructional part of the Christian worship service, consisting of hymns, prayers, scriptural readings, and homilies, which precedes the Eucharist (i.e., the Liturgy of the Faithful). In the early church the catechumens, or hearers who had not yet been baptized, ...
categorical imperative: in the ethics of the 18th-century German philosopher Immanuel Kant, founder of critical philosophy, a moral law that is unconditional or absolute for all agents, the validity or claim of which does not depend on any ulterior motive or end. ...
categorical proposition: in syllogistic or traditional logic, a proposition or statement, in which the predicate is, without qualification, affirmed or denied of all or part of the subject. Thus, categorical propositions are of four basic forms: "Every S is P," "No S ...
category: in logic, a term used to denote the several most general or highest types of thought forms or entities, or to denote any distinction such that, if a form or entity belonging to one category is substituted into a statement ...