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Definitions

undo

[uhn-doo] / ʌnˈdu /
VERB
open
Synonyms
STRONGEST
loosen unlock unravel
STRONG
disengage disentangle free loose release unbind unblock unbutton unfasten unloose unloosen untie unwrap
WEAK
unclose unfix unshut unstop
Antonyms
STRONG
button fasten
WEAK
close do up
VERB
nullify, invalidate
Synonyms
STRONGEST
abolish annul destroy mar negate offset overturn quash reverse ruin shatter spoil subvert undermine wipe out wreck
STRONG
abate abrogate annihilate break cancel cramp craze crimp decimate defeat demolish have impoverish injure neutralize outfox outmaneuver outsmart overreach overthrow raze skin smash stymie unsettle upset vitiate wrack
WEAK
bring down bring to naught make waves screw up unbuild
Antonyms
STRONGEST
aid allow assist build construct create grow help permit repair restore support uphold
STRONG
approve balance encourage establish fix mend revive save
WEAK
validate

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The war’s end threatens to undo all that.

From Barron's • Apr. 9, 2026

Nothing will ever undo the original sin, and devoting your life to ruining someone else’s is a loss for both of you.

From Los Angeles Times • Mar. 19, 2026

She added: "I recognise that any sentence imposed by this court will not undo what has been done, or repair or remove the hurt and grief suffered by them".

From BBC • Mar. 13, 2026

The company said the military’s latest proposal would effectively undo those guardrails.

From The Wall Street Journal • Feb. 26, 2026

Michael came and stood near her and watched her undo the string and tear away the brown paper.

From "Mary Poppins" by P. L. Travers

Vocabulary lists containing undo

Commonly Confused Words, List 3

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Commonly Confused Words, List 5

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Commonly Confused Words, List 7

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