/ Dictionary / Index I infidelity: Meaning and Definition of Find definitions for: in•fi•del•i•ty Pronunciation: (in"fi-del'i-tē), [key] — pl. -ties. marital disloyalty; adultery. unfaithfulness; disloyalty. lack of religious faith, esp. Christian faith. a breach of trust or a disloyal act; transgression. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: infidelity (Thesaurus) infidel infield Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language