Ā′er-ā′tion, n.

n. 1. (Chem.) The act or operation of combining with carbonic acid. [Obs.] 2. (Zool.) A change produced in the blood or circulating fluid of animals, by exposure to the air in respiration; arterialization. 3. (Agri.) The exposure of soil to the free action of the air, as essential to the growth of plants.