1. undo - Noun
2. undo - Adjective
3. undo - Verb
To reverse, as what has been done; to annul; to bring to naught.
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.
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.
Source: Webster's dictionaryYou can't undo the past... but you can certainly not repeat it. Bruce Willis
Shuffling is the only thing which Nature cannot undo. Arthur Eddington
A princely mind will undo a private family. George Savile, 1st Marquess of Halifax
With customs we live well, but laws undo us. English Proverb
A man cannot undo his past. can zebras wipe away their stripes? Namibian Proverb
Not even the lord of light can turn back time, or undo what has been done. Darkovan Proverb