/ Dictionary / Index G giantism: Meaning and Definition of Find definitions for: gi•ant•ism Pronunciation: (jī'un-tiz"um), [key] — n. gigantism. the state or quality of being a giant. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: giantism (Thesaurus) giant hornet giant kelp Related Content Daily Word Quiz: loquacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language