Dictionary definition · undo
verb
- cancel, annul, or reverse an action or its effect"I wish I could undo my actions"
- deprive of certain characteristics
- cause the ruin or downfall of"A single mistake undid the President and he had to resign"
- cause to become loose"undo the shoelace"
- remove the outer cover or wrapping of"Let's unwrap the gifts!"
Source: Open English WordNet (CC BY 4.0).