1. Remove the outer cover or wrapping of
   "undo the parcel";
   - unwrap
    
2. Cause to become loose
   "undo the shoelace";
   - untie
    
3. Cancel, annul, or reverse an action or its effect
   "I wish I could undo my actions"
    
4. Deprive of certain characteristics
   "God himself cannot unmake the past or undo what is done";
   - unmake
    
5. Cause the ruin or downfall of
   "A single mistake undid the President and he had to resign"

Derived forms: undid, undone, undoes, undoing

Type of: alter, change, expose, modify, reverse, ruin, turn, uncover

Antonym: make, wrap

Encyclopedia: Undo