undo

[ uhn-doo ]

/ ʌnˈdu /

SEE MORE SYNONYMS FOR undo ON THESAURUS.COM

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.

Nearby words

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 undo

But then the question becomes, how do you undo gerrymandering?
Seriously, Democrats: You’re Done in Dixie|Michael Tomasky|December 10, 2014|DAILY BEAST
And yet, ultimately, the Supreme Court holds the power to uphold or undo what it has taken him years to accomplish.
From POTUS to SCOTUS: Obama’s Big Move?|Keli Goff|November 17, 2014|DAILY BEAST
Underlying all of this legal maneuvering is the social fact that marriages are hard to undo.
Gay Marriage Chaos Begins|Jay Michaelson|November 11, 2014|DAILY BEAST
The wind and the dust in this climate can undo even the hardiest things.
Whatever You Do Someone Will Die. A Short Story About Impossible Choices in Iraq|Nathan Bradley Bethea|August 31, 2014|DAILY BEAST

He was trying to undo the Great Society, and he basically said that in his memoir.
The Real Legacy of Richard Nixon|Scott Porch|August 5, 2014|DAILY BEAST
Millner, as mechanically, took one of the virginally cinctured cigars, and began to undo its wrappings.
Tales Of Men And Ghosts|Edith Wharton
No healing process can help you here to undo your clumsy surgery and want of skill.
Blackwood's Edinburgh Magazine, Volume 60, No. 369, July 1846|Various
But now nothing could undo or deny that flash of fact, that for a second they had been glad to be interrupted.
The Ball and The Cross|G.K. Chesterton
A false move on our part might undo everything and ruin our cause.
Walter and the Wireless|Sara Ware Bassett
You might undo the work of weeks, make the patient's ultimate recovery doubtful.
The Higher Court|Mary Stewart Daggett

British Dictionary definitions for undo

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 undo

undo

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.

undo

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

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Origin of undo

Examples from the Web for undo

undo

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

undo