undo

Etymology 1

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

verb

1. To reverse the effects of an action.
   Fortunately, we can undo most of the damage to the system by the war.
   But Wigan undid their good work by conceding an avoidable second goal deep into first-half injury time. October 15, 2011, Michael Da Silva, “Wigan 1 - 3 Bolton”, in BBC Sport
   And judging by how well the progressive and youth-favoured party did, many observers suspect this latest round of legal charges are a response to Future Forward's commitment to undo the legacy of military rule and undertake democratic reforms. 2019-04-06, Caleb Quinley, “Thailand: Anti-military party leader faces sedition charges”, in Al Jazeera, Doha: Al Jazeera, retrieved 2019-04-06
2. To unfasten.
   Could you undo my buckle for me?
3. (figurative) To impoverish or ruin, as in reputation; to cause the downfall of.

noun

1. (computing) An operation that reverses a previous action.
   How many undos does this program support?

Etymology 2

adj

1. Misspelling of undue.