/ Dictionary / Index I impeccable: Meaning and Definition of Find definitions for: im•pec•ca•ble Pronunciation: (im-pek'u-bul), [key] — adj. faultless; flawless; irreproachable: impeccable manners. not liable to sin; incapable of sin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: impeccable (Thesaurus) impearl impecunious 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