Pronunciation: (grOOp), [key]
1. any collection or assemblage of persons or things; cluster; aggregation: a group of protesters; a remarkable group of paintings.
2. a number of persons or things ranged or considered together as being related in some way.
3. Also called radical. Chem.two or more atoms specifically arranged, as the hydroxyl group, –OH. Cf. free radical.
a. (in the classification of related languages within a family) a category of a lower order than a subbranch and of a higher order than a subgroup: the Low German group of West Germanic languages.
b. any grouping of languages, whether it is made on the basis of geography, genetic relationship, or something else.
5. Geol.a division of stratified rocks comprising two or more formations.
a. Army.a flexible administrative and tactical unit consisting of two or more battalions and a headquarters.
b. Air Force. an administrative and operational unit subordinate to a wing, usually composed of two or more squadrons.
7. Music.a section of an orchestra comprising the instruments of the same class.
8. Art.a number of figures or objects shown in an arrangement together.
9. Math.an algebraic system that is closed under an associative operation, as multiplication or addition, and in which there is an identity element that, on operating on another element, leaves the second element unchanged, and in which each element has corresponding to it a unique element that, on operating on the first, results in the identity element.
10. Gram. Chiefly Brit.a phrase: nominal group; verbal group.
1. to place or associate together in a group, as with others.
2. to arrange in or form into a group or groups.
1. to form a group.
2. to be part of a group.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.