Thesaurus.com
Dictionary.com
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 California Faculty Association said the verdict, while welcome, could not undo the harm Caravello endured, adding that its members would continue working to protect immigrant communities.

From Los Angeles Times • Apr. 10, 2026

The war’s end threatens to undo all that.

From Barron's • Apr. 9, 2026

Adam Sharp, representing Askari, said nothing could be said that could "undo or lessen the utter devastation" caused by Veisi's death and asked that the court consider Askari's "longstanding mental illness" when determining sentence.

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

Each time she did it, she shook her head and started to undo it.

From "The Night Diary" by Veera Hiranandani

Vocabulary lists containing undo

Commonly Confused Words, List 3

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

Commonly Confused Words, List 5

Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!

Commonly Confused Words, List 7

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!