Irrevocable \Ir*rev"o*ca*ble\, a. [L. irrevocabilis: cf. F. irr['e]vocable. See {In-} not, and {Revoke}, and cf. {Irrevocable}.] Incapable of being recalled or revoked; unchangeable; irreversible; unalterable; as, an irrevocable promise or decree; irrevocable fate. Firm and irrevocable is my doom. --Shak. -- {Ir*rev"o*ca*ble*ness}, n. -- {Ir*rev"o*ca*bly}, adv.