undo

verb

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

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
3
a
: 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
undoer noun

Examples of undo in a Sentence

You can't undo the past. The damage cannot be undone. He was undone by greed.
Recent Examples on the Web The decision by an 11-judge 9th Circuit panel undoes one made last year by a three-judge panel of the same court. Kevin Rector, Los Angeles Times, 10 June 2024 As brilliant as Doncic was in the quarter, all of his work was ultimately undone as the Celtics went on a 14-0 run. Steven Johnson, Fort Worth Star-Telegram, 7 June 2024 And what is done by a ballot measure can only be undone by a ballot measure. Jennah Pendleton, Sacramento Bee, 21 May 2024 While it hasn’t been confirmed how many people purchased the Class A stock during the technical error—which lasted for around an hour and a half—the New York Stock Exchange (NYSE) has swiftly undone all their trades. Byeleanor Pringle, Fortune, 4 June 2024 See all Example Sentences for undo 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'undo.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

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

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

Dictionary Entries Near undo

Cite this Entry

“Undo.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/undo. Accessed 24 Jun. 2024.

Kids Definition

undo

verb
un·​do ˌən-ˈdü How to pronounce undo (audio)
ˈən-
undid -ˈdid How to pronounce undo (audio) ; undone -ˈdən How to pronounce undo (audio) ; undoing -ˈdü-iŋ How to pronounce undo (audio)
1
: to make or become unfastened or loosened : open, untie
undo a knot
2
: to destroy the effect of : nullify, reverse
3
a
: to cause the ruin of
your stubbornness undid you
undone by greed
b
: to disturb the calmness of : upset
she's come undone
undoer noun

More from Merriam-Webster on undo

Last Updated: - Updated example sentences
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