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

Short of undoing global warming, researchers say giant sequoias stand a much better chance of survival with better forest management. Kurtis Alexander, SFChronicle.com, "Giant sequoias — long survivors of the forest — succumbing to climate-driven wildfires," 12 Sep. 2019 The justices’ order late Wednesday temporarily undoes a lower-court ruling that had blocked the new asylum policy in some states along the southern border. Mark Sherman, The Denver Post, "Supreme Court allows nationwide enforcement of new Trump administration restrictions on asylum seekers," 11 Sep. 2019 The effort undid a St. Ignatius burst ignited by Cmiel. Matt Goul, cleveland.com, "No. 2 Mentor digs deep to beat No. 3 St. Ignatius, 38-31," 6 Sep. 2019 Even knowing Bob’s messy matrix, Eve cannot undo his moves. Adrian Cho, Science | AAAS, "Cryptographers scramble to protect the internet from hackers with quantum computers," 21 Aug. 2019 The right policies can undo decades of economic segregation and racial wealth disparities, including recent damage that the current administration has inflicted on fair housing and anti-discrimination policies. Alissa Walker, Curbed, "Americans spend too much money on housing. Why aren’t the candidates talking about it?," 1 Aug. 2019 In the small hours of July 6th, Turkey’s president undid much of the recent progress by sacking Murat Cetinkaya, the head of the central bank. The Economist, "President Erdogan sacks Turkey’s central-bank head, risking a currency crisis," 8 July 2019 The rule undoes Obama-era guidance on HRAs and delivers on an October 2017 executive order from President Trump directing agencies to look at expanding HRAs. Stephanie Armour, WSJ, "Trump Administration Expands Pre-Tax Accounts for Health Insurance," 13 June 2019 Critics of the new immunization law hope to undo it with the 2020 ballot, but their path could be costly and difficult. Julia Wick, Los Angeles Times, "Newsletter: Essential California Week in Review: End-of-session rush in Sacramento," 14 Sep. 2019

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

21 Oct 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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