/ Dictionary / Index G G.C.D.: Meaning and Definition of Find definitions for: G.C.D. Pronunciation: [key] greatest common divisor. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. GCC GCE Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language