(mathematics, geometry, algebra) A group whose elements are all the transformations under which a given object remains invariant and whose group operation is function composition.

(mathematics) A group of Lie type over a finite field constructed from an exceptional automorphism of a Dynkin diagram that reverses the direction of the multiple bonds, generalizing the Suzuki group.

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

A rank in the RAF, between that of wing commander and air commodore, equivalent to an army colonel

(phylogenetics) The living representatives of a collection of species, together with their ancestors back to their most recent common ancestor as well as all of that ancestor's descendants.

(physics) A mathematical apparatus that allows systematic investigation of the changes of a physical system as viewed at different distance scales.

A group adding impetus or spirit on a particular topic, especially within a political party or other organization.

plural of group ring

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

(rare) A group theorist.