Definition of air

• a mixture of gases (especially oxygen) required for breathing; the stuff that the wind consists of; "air pollution"; "a smell of chemicals in the air"; "open a window and let in some air"; "I need some fresh air"
• travel via aircraft; "air travel involves too much waiting in airports"; "if youve time to spare go by air"
• the region above the ground; "her hand stopped in mid air"; "he threw the ball into the air"