/ Dictionary / Index G groupoid: Meaning and Definition of Find definitions for: group•oid Pronunciation: (gr'poid), [key] — n. Math. an algebraic system closed under a binary operation. Also calledCf. group (def. 9), Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. group marriage group practice Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language