/ Dictionary / Index U undoing: Meaning and Definition of Find definitions for: un•do•ing Pronunciation: (un-d'ing), [key] — n. the reversing of what has been done; annulling. a bringing to destruction, ruin, or disaster. a cause of destruction or ruin. the act of unfastening or loosing. an unconscious defense mechanism through which an attempt is made to reverse a psychologically unacceptable act by doing its opposite, usually repetitiously, in order to relieve anxiety. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: undoing (Thesaurus) undocumented undone Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language