Definitions
1.VerbTo reverse the effects of an action."Fortunately, we can undo most of the damage to the system by the war.; What's done can't be undone."
2.VerbTo unfasten."Could you undo my buckle for me?"
3.VerbTo unfasten the clothing of (a person).
4.VerbTo impoverish or ruin, as in reputation; to cause the downfall of.
5.NounAn operation that reverses a previous action."How many undos does this program support?"
6.AdjectiveMisspelling of undue.