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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Find it on Amazon Handmade Kent 9T Graphite Hair Comb for Gentle Untangling Handmade from cellulose acetate, this saw-cut comb gently glides through short, long, straight, curly, fine, and coarse hair to tenderly undo tangles and remove knots. Hyphensocial Contributors, Rolling Stone, 6 Dec. 2024 Everything done through unilateral executive action can be undone through unilateral executive action. Abc News, ABC News, 5 Dec. 2024 His role, as a flawed genius who suffers for his art but is undone by his hubris, his drug addiction and the cutoff of his wealthy employer’s patronage, is harrowing. David Rooney, The Hollywood Reporter, 5 Dec. 2024 But despite promises to undo Joe Biden’s clean energy legacy, Trump’s team hasn’t specifically targeted funding from the Bipartisan Infrastructure Law as much, which funds the initiative. Justine Calma, The Verge, 27 Nov. 2024 See all Example Sentences for undo 

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 21 Dec. 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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