1. open (a jacket, package, door, etc.), release, unloose; cancel, revoke, reverse, annul; bring to ruin (emotionally, morally, etc.). cancellation of an action; ability of a program to cancel the most recent action (Computers). undo\un*do"\ , v. t. [as. und n. see:
1st un-, and do to perform.].
2. to reverse, as what has been done; to annul; to bring to naught. what's done can not be undone. to-morrow, ere the setting sun, she 'd all undo that she had done.
3. to loose; to open; to take to piece; to unfasten; to untie; hence, to unravel; to solve; as, to undo a knot; to undo a puzzling question; to undo a riddle. pray you, undo this button. she took the spindle, and undoing the thread gradually, measured it. w. scott.
4. to bring to poverty; to impoverish; to ruin, as in reputation, morals, hopes, or the like; as, many are undone by unavoidable losses, but more undo themselves by vices and dissipation, or by indolence. that quaffing and drinking will undo you,undo v.
5. cancel, annul, or reverse an action or its effect; "i wish i could undo my actions".
6. deprive of certain characteristics [syn: unmake] [ant: do].
7. cause the ruin or downfall of; "a single mistake undid the president and he had to resign".
8. cause to become loos; "undo the shoelace"; "untie the knot"; "loosen the necktie" [syn: untie, loosen].
9. remove the outer cover or wrapping of; "let's unwrap the gifts!"; "undo the parcel" [syn: unwrap] [ant: wrap].
10. To reverse, as what has been done; to annul; to bring to naught.
11. To loose; to open; to take to piece; to unfasten; to untie; hence, to unravel; to solve; as, to undo a knot; to undo a puzzling question; to undo a riddle.
12. To bring to poverty; to impoverish; to ruin, as in reputation, morals, hopes, or the like; as, many are undone by unavoidable losses, but more undo themselves by vices and dissipation, or by indolence. cancel, annul, or reverse an action or its effect; "I wish I could undo my actions" cause the ruin or downfall of; "A single mistake undid the President and he had to resign".
13. 1. If you undo something that is closed, tied, or held together, or if you undo the thing holding it, you loosen or remove the thing holding it. I managed secretly to undo a corner of the parcel Some clamps that had held the device together came undone.
14. To undo something that has been done means to reverse its effect. She knew it would be difficult to undo the damage that had been done If Michael won, he would undo everything I have fought for. see also:
undoing, undone.