the flow of air; "she adjusted the fan so that the airflow was directed right at her"

air will flow from an area of higher pressure to one of lower pressure; during inspiration, the pressure in the alveoli (lung tissue) must be less than the pressure at the mouth for air to flow in, and during expiration, the reverse is true.

as in volume air flow rate needed to transfer heat

Air gap Air gun

The motion of air relative to a body in it.

The distribution or movement of air.