[ uhn-doo-ing ]
/ ʌnˈdu ɪŋ /


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.
Psychiatry. 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.

Origin of undoing

Middle English word dating back to 1300–50; see origin at undo, -ing1

Related forms

self-un·do·ing, adjective

Definition for undoing (2 of 2)


[ uhn-doo ]
/ ʌnˈdu /

verb (used with object), un·did, un·done, un·do·ing.

Origin of undo

before 900; Middle English; Old English undōn; cognate with Dutch ontdoen. See un-2, do1

Related forms

un·do·a·ble, adjective

Can be confused

undo undue
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for undoing

British Dictionary definitions for undoing (1 of 2)


/ (ʌnˈduːɪŋ) /


ruin; downfall
the cause of downfalldrink was his undoing

British Dictionary definitions for undoing (2 of 2)


/ (ʌnˈduː) /

verb -does, -doing, -did or -done (mainly tr)

(also intr) to untie, unwrap, or open or become untied, unwrapped, etc
to reverse the effects of
to cause the downfall of
obsolete to explain or solve

Derived Forms

undoer, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012