/ Dictionary / Index U unfaithful: Meaning and Definition of Find definitions for: un•faith•ful Pronunciation: (un-fāth'ful), [key] — adj. not faithful; false to duty, obligation, or promises; faithless; disloyal. not sexually faithful to a spouse or lover. not accurate or complete; inexact: an unfaithful translation. unbelieving; infidel. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: unfaithful (Thesaurus) unfair practice unfamiliar Related Content Daily Word Quiz: crutiny Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language