/ Dictionary / Index U unable: Meaning and Definition of Find definitions for: un•a•ble Pronunciation: (un-ā'bul), [key] — adj. lacking the necessary power, competence, etc., to accomplish some specified act: He was unable to swim. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: unable (Thesaurus) unabated unabridged Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language