Real Dictionary

air
Air is used to refer to travel in aircraft.
singular noun: The air is the space around things or above the ground.
uncountable noun: Air is the mixture of gases which forms the Earth's atmosphere and which we breathe.

Aïr in American English
mountainous region of the S Sahara, in NC Niger: c. 30,000 sq mi (77,700 sq km)
the elastic, invisible mixture of gases (chiefly nitrogen and oxygen, as well as hydrogen, carbon dioxide, argon, neon, helium, etc.) that surrounds the earth; atmosphere

air in American English 1
noun: a mixture of nitrogen, oxygen, and minute amounts of other gases that surrounds the earth and forms its atmosphere

air in American English 2
adjective: early
adverb: before; previously

air in British English
abbreviation for: All India Radio
noun: a mountainous region of N central Niger, in the Sahara, rising to 1500 m (5000 ft): a former native kingdom. Area: about 77 700 sq km (30 000 sq miles)
noun: the mixture of gases that forms the earth's atmosphere. At sea level dry air has a density of 1.226 kilograms per cubic metre and consists of 78.08 per cent nitrogen, 20.95 per cent oxygen, 0.93 per cent argon, 0.03 per cent carbon dioxide, with smaller q