v. 1 intr. (of a period of time, validity, etc.) come to an end. 2 intr. (of a document, authorization, etc.) cease to be valid; become void. 3 intr. (of a person) die. 4 tr. (usu. foll. by from; also absol.) exhale (air etc.) from the lungs. expiratory adj. (in sense 4).
[ ME f. OF expirer f. L exspirare (as EX-(1), spirare breathe) ]