undo

undo (http://definr.com/undo)

     v 1: cancel, annul, or reverse an action or its effect; "I wish I
          could undo my actions"
     2: deprive of certain characteristics [syn: unmake] [ant: do]
     3: cause the ruin or downfall of; "A single mistake undid the
        President and he had to resign"
     4: cause to become loos; "undo the shoelace"; "untie the knot";
        "loosen the necktie" [syn: untie, loosen]
     5: remove the outer cover or wrapping of; "Let's unwrap the
        gifts!"; "undo the parcel" [syn: unwrap] [ant: wrap]