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

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. 2019

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.

    The Daily Beast logo
    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


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



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.

Online Etymology Dictionary, © 2010 Douglas Harper