/ Dictionary / Index G GUI: Meaning and Definition of Find definitions for: GUI Pronunciation: (g'ē), [key] — pl. GUIs, GUI's. See Gui. Pronunciation: [key] Guiana. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: gui (Thesaurus) guglet Guiana Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language