Expiration \Ex`pi*ra"tion\, n. [L. expiratio,exspiratio: cf. F. expiration. See Expire.]

1. The act of expiring; as:
   (a) (Physiol.) 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.
   (b) Emission of volatile matter; exhalation.

The true cause of cold is an expiration from the globe of the earth. --Bacon.
   (c) The last emission of breath; death. ``The groan of expiration.'' --Rambler.
   (d) 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.

Source: Webster's Revised Unabridged Dictionary (1913)