English Reference
verb · noun

undo

v. · n.
US /ənˈdu/ UK /ʌndˈuː/ un·do UK spelling undoes

infinitive undo past undid past participle undone

  1. 01 B1 Intermediate

    v.to cancel the effect of something that was done before.

    v.to reverse the effects or consequences of a previous action or decision.

    Simple

    It is difficult to undo the damage caused by a bad reputation.

    In context

    The new administration sought to undo several of the previous government's most controversial environmental policies within its first hundred days.

  2. 02 B1 Intermediate

    v.to open something that is tied, buttoned, or zipped.

    v.to unfasten, untie, or loosen a physical connection or closure.

    Simple

    He had to undo his seatbelt before he could get out of the car.

    In context

    She struggled to undo the intricate silk knots on the parcel without tearing the delicate decorative paper.

    Pitfall
    I need to unfasten my shoes. I need to undo my shoelaces.

    While 'unfasten' is correct, 'undo' is the more natural choice for shoelaces, buttons, and knots.

    untieunfastenloosen
  3. 03 C1 Advanced Literary

    v.to cause someone to fail or lose their reputation.

    v.to bring to ruin or destruction; to cause the downfall of a person or entity.

    Simple

    His greed would eventually undo him and his entire family.

    In context

    It was ultimately his stubborn refusal to listen to his advisors that would undo his long and otherwise successful career in diplomacy.

  4. 04 B1 Intermediate Computing

    n.a button or command that cancels the last thing you did on a computer.

    n.a function within a software application that reverses the most recent operation and restores the document to its previous state.

    Simple

    If you make a mistake while typing, just click undo.

    In context

    The application supports multiple levels of undo, allowing the designer to revert through several hours of incremental changes if necessary.


From Middle English undōn, from Old English ondōn, from Proto-West Germanic *andadōn (“to undo”), equivalent to un- + do. Cognate with West Frisian ûndwaan, ûntdwaan (“to undo; rid”), Dutch ontdoen (“to undo”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin gmw-pro *andadōn
Level B1 · Intermediate
Frequency Frequent
Updated