• (America, British) IPA: /ʌnˈduː/

undo (undoes, present participle undoing; past undid, past participle undone) (transitive)

1. To reverse the effects of an action.

   Fortunately, we can undo most of the damage to the system by the war.

   • 1610–1611, William Shakespeare, “The Tempest”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act I, scene ii], page 4 ↗, column Pro.}} […] it was a torment / To lay vpon the damn'd, which Sycorax / Could not againe vndoe ; it was mine Art, / When I arriu'd, and heard thee, that made gape / The Pyne, and let thee out.:

     {w

2. To unfasten.

   Could you undo my buckle for me?

3. (figuratively) To impoverish or ruin, as in reputation; to cause the downfall of.
   • 1611, King James Bible

     Woe is me, for I am undone!

• (reverse effects) cancel, reverse
• (unfasten) unbuckle, unbutton, untie, unzip

• (reverse effects) redo
• (unfasten) do up, button, button up, tie up, zip, zip up,

• French: annuler, défaire
• German: rückgängig machen, ungeschehen machen
• Italian: annullare, disfare
• Portuguese: desfazer
• Russian: отменя́ть
• Spanish: deshacer

• French: défaire, délier
• German: aufmachen, öffnen, losmachen, lösen, abschnallen
• Italian: slacciare
• Portuguese: desatar
• Russian: расстёгивать
• Spanish: desatar

undo (plural undos)

1. (computing) An operation that reverses a previous action.

   How many undos does this program support?

1. Misspelling of undue