/ Dictionary / Index G giant tortoise: Meaning and Definition of Find definitions for: gi'ant tor'toise Pronunciation: [key] any of several large tortoises of the genus Geochelone, of the Galápagos Islands and islands near Madagascar: some are endangered. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. giant sunflower giant water bug Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language