verb
undo
uhn-DOO
verb
1
To reverse or cancel the effect of something already done.
"You can undo your last edit with Ctrl+Z."
"It took years to undo the damage caused by the flood."
2
To unfasten something, such as a knot, button, or zip.
"She undid the top button of her coat."
3
To ruin someone or bring about their downfall.
"A single careless remark undid his entire campaign."
noun
1
A command or action that reverses the previous one, especially in software.
"Every good text editor supports undo."
How to Use Undo
Learner’s notesIn plain EnglishTo reverse something — put it back the way it was, unfasten it, or ruin it.
Common pairings
undo a mistake
undo the damage
undo a button
press undo
Word Forms
undid past tense, undone past tense, undos plural, undoes singular
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You can _____ your last edit with Ctrl+Z.
Etymology
From Old English ondōn, from a Germanic root meaning "to do the opposite of" — un- plus do.