undo

[ uhn-doo ]

verb (used with object)

, un·did [uhn-, did], un·done [uhn-, duhn], un·do·ing.

1. to reverse the doing of; cause to be as if never done:

   Murder once done can never be undone.

2. to do away with; erase; efface:

   to undo the havoc done by the storm.

3. to bring to ruin or disaster; destroy:

   In the end his lies undid him.

4. to unfasten by releasing:

   to undo a gate; to undo a button.

5. to untie or loose (a knot, rope, etc.).
6. to open (a package, wrapping, etc.).
7. Archaic. to explain; interpret.

undo

/ ʌnˈduː /

verb

1. also intr to untie, unwrap, or open or become untied, unwrapped, etc
2. to reverse the effects of
3. to cause the downfall of
4. obsolete.
   to explain or solve

Derived Forms

• unˈdoer, noun

Other Words From

• un·doa·ble adjective

Word History and Origins

Origin of undo¹

First recorded before 900; Middle English; Old English undōn; cognate with Dutch ontdoen; un- ², do ¹

Example Sentences

But the very thing that make phages so promising — their ability to evolve in step with pathogens — has been their undoing at the Food and Drug Administration, at least until recently.

From Salon

Voters overwhelmingly supported a ballot measure to undo a decade of progressive criminal justice reform, and rejected an initiative that would have banned forced prison labor.

From Los Angeles Times

They will help determine whether Trump can undo the checks and balances the founders wrote into the Constitution, and turn the executive branch into an instrument of a would-be autocrat’s will.

From Los Angeles Times

He did, after all, urge oil executives to underwrite his latest campaign in exchange for undoing environmental rules.

From Los Angeles Times

Perhaps most importantly, Mr. Trump says he will undo many of Mr. Biden’s attempts to tackle the climate crisis.

From NewsForKids.net

Related Words

• abolish
• annul
• destroy
• mar
• negate
• offset
• overturn
• quash
• reverse
• ruin
• shatter
• spoil
• subvert
• undermine
• wipe out
• wreck