1. (Bot.)

Defn: A cavity in the cellular tissue of plants, containing air only.

2. (Anat.)

Defn: A receptacle of air in various parts of the system; as, a cell or minute cavity in the walls of the air tubes of the lungs; the air sac of birds; a dilatation of the air vessels in insects.

AIR CHAMBER
Air" cham`ber.

1. A chamber or cavity filled with air, in an animal or plant.

2. A cavity containing air to act as a spring for equalizing the flow of a liquid in a pump or other hydraulic machine.

AIR COCK
Air" cock`.

Defn: A faucet to allow escape of air.

AIR COOLING
Air cooling.