undo

verb
un·​do | \ ˌən-ˈdü How to pronounce undo (audio) , ˈən-\
undid\ ˌən-​ˈdid How to pronounce undid (audio) , ˈən-​ \; undone\ ˌən-​ˈdən How to pronounce undone (audio) , ˈən-​ \; undoing\ ˌən-​ˈdü-​iŋ How to pronounce undoing (audio) , ˈən-​ \

Definition of undo

transitive verb

1 : to open or loose by releasing a fastening
2 : to make of no effect or as if not done : make null : reverse
3a : to ruin the worldly means, reputation, or hopes of a politician undone by scandal
b : to disturb the composure of : upset she's come undone

intransitive verb

: to come open or apart

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Other Words from undo

undoer \ ˌən-​ˈdü-​ər How to pronounce undoer (audio) , ˈən-​ \ noun

Synonyms & Antonyms for undo

Synonyms

demoralize, emasculate, paralyze, unman, unnerve, unstring

Antonyms

nerve

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Examples of undo in a Sentence

You can't undo the past. The damage cannot be undone. He was undone by greed.
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Recent Examples on the Web

Unfortunately for Trump, a wall can’t undo 100 years of damage even if a national emergency is declared. Lucy Diavolo, Teen Vogue, "Donald Trump Is Threatening to Declare a National Emergency to Get Border Wall Funding. Here's Why He Shouldn’t.," 11 Jan. 2019 That formed so much of my identity and took so many years to undo. Matthew Sprout, Allure, "Margarita Levieva on Ageism in Hollywood and Playing Characters 10 Years Younger Than Herself," 16 Oct. 2018 That all the good LeBron did in 40 minutes could nearly be undone in eight speaks to the gravity of the competition. Rob Mahoney, SI.com, "Pacers Earn the Wrath of a Resolute LeBron James," 18 Apr. 2018 Soon to take effect, the ban would undo a 2016 Obama administration policy granting the trans community its first-ever opportunity to serve openly in the armed forces. Thomas Voting Reports, The Seattle Times, "How Your U.S. Lawmaker Voted," 30 Mar. 2019 Massachusetts' Gender Identity Anti-Discrimination Veto Referendum—would undo all of it. Jenny Hollander, Marie Claire, "This Anti-Trans Ballot Measure in Massachusetts Must Be Stopped," 3 Oct. 2018 The Wisconsin Supreme Court on Friday undid 2013 changes to the City of Milwaukee's pension board, which the court said unlawfully diluted the voice of police and firefighters on the board. Bruce Vielmetti, Milwaukee Journal Sentinel, "Supreme Court gives Milwaukee police greater voice on pension board," 6 July 2018 This could undo all the good the tax cuts have done and derail what could the best economy of the recovery. NBC News, "Trade war threatens continued job growth, economists say," 6 July 2018 While Trump bent to pressure last week and signed an executive order undoing his own administration’s policy, many children have not been reunited with their families. Steve Annear, BostonGlobe.com, "Salem kids write heartfelt letters to immigrant children separated at border," 27 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'undo.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of undo

before the 12th century, in the meaning defined at transitive sense 1

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Dictionary Entries near undo

undivined

undivinely

undivulged

undo

undoable

undocile

undock

Statistics for undo

Last Updated

20 May 2019

Look-up Popularity

Time Traveler for undo

The first known use of undo was before the 12th century

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More Definitions for undo

undo

verb

English Language Learners Definition of undo

: to open or release (something) : to unfasten or loosen (something)
: to change or stop the effect of (something)
formal : to cause the failure of (someone or something)

undo

verb
un·​do | \ ˌən-ˈdü How to pronounce undo (audio) \
undid\ -​ˈdid \; undone\ -​ˈdən \; undoing\ -​ˈdü-​iŋ \; undoes\ -​ˈdəz \

Kids Definition of undo

1 : untie sense 2, unfasten Can you undo this knot?
2 : to cancel the effect of : reverse The damage cannot be undone.
3 : to cause the ruin or failure of He was undone by greed.

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More from Merriam-Webster on undo

Rhyming Dictionary: Words that rhyme with undo

Thesaurus: All synonyms and antonyms for undo

Spanish Central: Translation of undo

Nglish: Translation of undo for Spanish Speakers

Britannica English: Translation of undo for Arabic Speakers

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