undo Meaning, Definition & Usage

verb cancel, annul, or reverse an action or its effect
- I wish I could undo my actions
verb deprive of certain characteristics
unmake.
verb cause the ruin or downfall of
- A single mistake undid the President and he had to resign
verb cause to become loose
loosen; untie.
- undo the shoelace
- untie the knot
- loosen the necktie
verb remove the outer cover or wrapping of
unwrap.
- Let's unwrap the gifts!
- undo the parcel

AS. undn. See 1st Un-, and Do to perform.

To reverse, as what has been done; to annul; to bring to naught.
What's done can not be undone. Shak.

To-morrow, ere the setting sun, She 'd all undo that she had done. Swift.
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. Tennyson.
Pray you, undo this button. Shak.

She took the spindle, and undoing the thread gradually, measured it. Sir W. Scott.
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, Shak.