1. A reason that justifies an act or omission or that relieves a person of a duty.
2. Criminal law. A defense that arises because the defendant is not blameworthy for having acted in a way that would otherwise be criminal. • The following defenses are the traditional excuses: duress, entrapment, infancy, insanity, and involuntary intoxication. — Also termed legal excuse. Cf. JUSTIFICATION(2). [Cases: Criminal Law 37–38. C.J.S. Criminal Law §§ 49–53, 58.] — excuse (ek-skyooz), vb. — excusatory (ek-skyooz-[schwa]-tor-ee), adj.