undo
Americanverb (used with object)
-
to reverse the doing of; cause to be as if never done.
Murder once done can never be undone.
-
to do away with; erase; efface.
to undo the havoc done by the storm.
-
to bring to ruin or disaster; destroy.
In the end his lies undid him.
-
to unfasten by releasing.
to undo a gate; to undo a button.
-
to untie or loose (a knot, rope, etc.).
-
to open (a package, wrapping, etc.).
-
Archaic. to explain; interpret.
verb
-
(also intr) to untie, unwrap, or open or become untied, unwrapped, etc
-
to reverse the effects of
-
to cause the downfall of
-
obsolete to explain or solve
Other Word Forms
- undoable adjective
- undoer noun
Etymology
Origin of undo
First recorded before 900; Middle English; Old English undōn; cognate with Dutch ontdoen; un- 2, do 1
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.
In September, the company said it would split in two, undoing the 2015 deal.
It’s always easier to prevent bad behavior than to undo it.
From MarketWatch
Three months ago, another international team of scientists involving researchers in China, Spain and the U.K. also found they were able to undo physical brain damage in mice that resulted from Alzheimer’s.
From MarketWatch
Backed into a corner by the threat of a career-ending scandal—one that would not only undo her but also her blithely trusting editor — Elizabeth agrees to make the fantasy corporeal.
From Salon
At the center of the work is a way to undo a built in "brake" that tumors can trigger to keep immune cells from attacking.
From Science Daily
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.