[ uhn-did ]
/ ʌnˈdɪd /


simple past tense of undo.

Nearby words

  1. undetermined nitrogen,
  2. undeterred,
  3. undeveloped,
  4. undeviating,
  5. undiagnosed,
  6. undies,
  7. undifferentiated,
  8. undifferentiated type fever,
  9. undigested,
  10. undigestible


[ 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 formsun·do·a·ble, adjective

Can be confusedundo undue

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

Examples from the Web for undid

British Dictionary definitions for undid


/ (ʌnˈdɪd) /


the past tense of undo


/ (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 Formsundoer, 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

Word Origin and History for undid



Old English undon "to unfasten and open" (a window or door), "to unfasten by releasing from a fixed position," from un- (2) + do (v.). The notion is of "to annul something that was done." Related: Undone; undoing.

Online Etymology Dictionary, © 2010 Douglas Harper