Air

[1] Abbreviation for "air conditioner".
[2] A bicycling or motorcycling term describing the space or gap between the tires and the ground when the bike takes a jump. Both tires must be off the ground before it can be called "air" as in the expression, "I really caught air on that last jump".
[3] A gas containing approximately 80% nitrogen, 20% oxygen, and a small portion of other gases. One of the essential factors in a combustion engine (fuel, air, proper proportion of mixture, compression, timing, and spark).
See also ambient air, bath air, charge air, cold air, driver air bag, electric air control valve, electric air switching valve, external mix air cap, fuel air mixture, fuel air ratio, heater air pipe, idle air bleed screw, idle air jet, internal mix air cap, L-jetronic air flow meter, lateral air passage, low-profile air cleaner, modular air strut, oil bath air cleaner, paper air cleaner, passenger-side air bag, proper proportion of air and fuel, pulse air principle, pulse air system, ram air, secondary air