/ Dictionary / Index A additive identity: Meaning and Definition of Find definitions for: ad'ditive iden'tity Pronunciation: [key] — Math. Math. an element that when added to a given element in a specified set leaves that element unchanged, as zero in the real-number system. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. additive group additive inverse Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language