n. The act of expiringn. The act or process of breathing out, or forcing air from the lungs through the nose or mouth; as, respiration consists of inspiration and expiration; -- opposed to inspiration.n. Emission of volatile matter; exhalation.n. The last emission of breath; death.n. A coming to a close; cessation; extinction; termination; end.n. That which is expired; matter breathed forth; that which is produced by breathing out, as a sound.