expirationn.[L. expiratio,exspiratio: cf. F. expiration. See Expire.]1. (Physiol.) The act of expiring()The true cause of cold is an expiration from the globe of the earth. (Bacon.) The last emission of breath; death.(Rambler.) A coming to a close; cessation; extinction; termination; end.()Before the expiration of thy time. (Shak.)2. That which is expired; matter breathed forth; that which is produced by breathing out, as a sound.()The aspirate he, which is . . . a gentle expiration. (G. Sharp.)