A mixture of hydrogen and air used as fuel to a fuel cell. / (obsolete, chemistry) An early term for hydrogen; hydrogen gas.

(meteorology) A particular volume of air, especially one having a roughly uniform temperature, pressure and water vapour content.

To mechanically cool a space or an entire structure.

(idiomatic) To expose to air; to leave open or spread out, as to allow odor or moisture to dissipate. / (by extension) To discuss in the open; to address an issue or conflict that has long been avoided.

Alternative form of airbridge.

(physics) The action of friction that slows something moving through air; drag.

Alternative spelling of airbrake

Alternative spelling of airspace

(idiomatic) Aggressive, disruptive behaviour on an aircraft.

Any recreational activity performed in flight or during freefall from a flight through the atmosphere.