/ Dictionary / Index E existence theorem: Meaning and Definition of Find definitions for: exist'ence the"orem Pronunciation: [key] — Math. Math. any theorem that asserts the existence of some specified mathematical object. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. existence existent Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language