Definition of "undo" in English

verb

1. To reverse the effects of an action.

   • Fortunately, we can undo most of the damage to the system by the war.
   • What's done can't be undone.

2. (transitive) To unfasten.

   • Could you undo my buckle for me?

3. (transitive, colloquial) To unfasten the clothing of (a person).

   • PROSTITUTE: Undo me. There's a dear.

4. (figuratively) 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?

adjective

1. Misspelling of undue.