| 1. | the reversing of what has been done; annulling. |
| 2. | a bringing to destruction, ruin, or disaster. |
| 3. | a cause of destruction or ruin. |
| 4. | the act of unfastening or loosing. |
| 5. | Psychiatry. an unconscious defense mechanism through which an attempt is made to reverse a psychologically unacceptable act by doing its opposite, usually repetitiously, in order to relieve anxiety. |
| 1. | to reverse the doing of; cause to be as if never done: Murder once done can never be undone. |
| 2. | to do away with; erase; efface: to undo the havoc done by the storm. |
| 3. | to bring to ruin or disaster; destroy: In the end his lies undid him. |
| 4. | to unfasten by releasing: to undo a gate; to undo a button. |
| 5. | to untie or loose (a knot, rope, etc.). |
| 6. | to open (a package, wrapping, etc.). |
| 7. | Archaic. to explain; interpret. |
un·do·ing (ŭn-dōō'ĭng) v. Present participle of undo. n.
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