verb (v)

• cancel, annul, or reverse an action or its effect(verb.contact)

  Example:
  I wish I could undo my actions.
  

  source: wordnet30
• deprive of certain characteristics(verb.creation)

  Synonym:
  unmake
  Antonym:
  do, make
  

  source: wordnet30
• cause the ruin or downfall of(verb.social)

  source: wordnet30
• cause to become loose(verb.contact)

  Example:
  Undo the shoelace.
  

  Synonym:
  loosen, untie
  

  source: wordnet30
• remove the outer cover or wrapping of(verb.contact)

  Example:
  Undo the parcel.
  

  Synonym:
  unwrap
  Antonym:
  wrap, wrap up
  

  source: wordnet30
• To reverse, as what has been done; to annul; to bring to naught.(verb)

  source: webster1913