undo

[uhn-doo]

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.

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. 2018

Examples from the Web for undo

Contemporary Examples

But then the question becomes, how do you undo gerrymandering?
Seriously, Democrats: You’re Done in Dixie
Michael Tomasky
December 10, 2014
We should undo that double standard by offering similar protections to every young Black man who is arrested in this country.
We Need More Ferguson-style Grand Juries
Kaimipono Wenger
November 30, 2014
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
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
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

Historical Examples

Come, captain, undo these ropes, and make up your mind quickly.
In the Midst of Alarms
Robert Barr
Come down, and undo the shop window, that I may get in that way.'
Barnaby Rudge
Charles Dickens
If a man can do whatever he thinks of—can he undo that which he has done?
Now We Are Three
Joe L. Hensley
No; but to go on as if hard work now can ever undo what years of idleness have done.
The First Violin
Jessie Fothergill
And, if I haply had erred, to undo the wrong, and release you.
Poems
William D. Howells

British Dictionary definitions for undo

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 undo

v.

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

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Examples from the Web for undo

Contemporary Examples

But then the question becomes, how do you undo gerrymandering?

We should undo that double standard by offering similar protections to every young Black man who is arrested in this country.

And yet, ultimately, the Supreme Court holds the power to uphold or undo what it has taken him years to accomplish.

Underlying all of this legal maneuvering is the social fact that marriages are hard to undo.

The wind and the dust in this climate can undo even the hardiest things.

Historical Examples

Come, captain, undo these ropes, and make up your mind quickly.

Come down, and undo the shop window, that I may get in that way.'

If a man can do whatever he thinks of—can he undo that which he has done?

No; but to go on as if hard work now can ever undo what years of idleness have done.

And, if I haply had erred, to undo the wrong, and release you.

undo

Word Origin and History for undo

v.

Origin of undo