late 14c., from Latin exhalationem (nominative exhalatio), noun of action from past participle stem of exhalare (see exhale).
exhalation ex·ha·la·tion (ěks'hə-lā'shən, ěk'sə-)
n.
The act or an instance of breathing out. Also called expiration.
The giving forth of gas or vapor.
Something, such as air or vapor, that is exhaled.
exhalation (ěks'hə-lā'shən) The act of breathing out air. During exhalation, the diaphragm relaxes and moves upward, causing compression of the lungs and an outward flow of air. Also called expiration. Compare inhalation. |