undo

[uhn-doo]

verb (used with object), un·did, un·done, un·do·ing.

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.

Origin of undo

before 900; Middle English; Old English undōn; cognate with Dutch ontdoen. See un-², do¹

Related formsun·do·a·ble, adjective

Can be confusedundo undue

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for undoable

Contemporary Examples of undoable

This trait ennobles the U.S. military, but also makes it highly vulnerable to taking on undoable tasks.
Obama's Afghan Nightmare
Leslie H. Gelb
June 16, 2010

Historical Examples of undoable

The dirty fist in the young surgeon's pocket was obliged to undoable itself, and come out of its ambush disarmed.
The History of Pendennis
William Makepeace Thackeray

British Dictionary definitions for undoable

undo

verb -does, -doing, -did or -done (mainly tr)

(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

Derived Formsundoer, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for undoable

undo

Old English undon "to unfasten and open" (a window or door), "to unfasten by releasing from a fixed position," from un- (2) + do (v.). The notion is of "to annul something that was done." Related: Undone; undoing.