simple past tense of undo.



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

to reverse the doing of; cause to be as if never done: Murder once done can never be undone.
to do away with; erase; efface: to undo the havoc done by the storm.
to bring to ruin or disaster; destroy: In the end his lies undid him.
to unfasten by releasing: to undo a gate; to undo a button.
to untie or loose (a knot, rope, etc.).
to open (a package, wrapping, etc.).
Archaic. to explain; interpret.

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

Contemporary Examples of undid

  • We undid it and hung it up in the kitchen, right next to a Nancy Newsom ham, the smell absolutely intoxicating.

    The Daily Beast logo
    Easter's Top Five Hams

    Mark Scarbrough

    March 30, 2010

Historical Examples of undid

  • Panting, she undid the scarf and flooded the room with light.

  • The Prince stood by the window and undid the packet with trembling hands.

  • She took down the parcel from the shelf and undid the string.

  • Juve relighted the lamp, and undid the black serge covering of the bundle.

    A Nest of Spies

    Pierre Souvestre

  • He undid the wrapping of the lawyer's letter and, as he read, the blood went from his face.

    Murder Point

    Coningsby Dawson

British Dictionary definitions for undid



the past tense of undo


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