(medicine) The basic system of categorizing blood by antigen type.

A group of musicians who regularly perform together.

plural of music group

Alternative form of abelian group

plural of Abelian group

plural of galaxy group

(astronomy) A group of galaxies that hold together gravitationally.

(group theory) A group obtained from a larger group by aggregating elements via an equivalence relation that preserves group structure.

(group theory) The unique group (up to isomorphism) consisting of a single element (which is the identity element).

(group theory) A group which has no normal subgroups apart from the trivial group and itself.