Why is the ninth month called September?
c.1300, "invisible gases that make up the atmosphere," from Old French air "atmosphere, breeze, weather" (12c.), from Latin aerem (nominative aer) "air, lower atmosphere, sky," from Greek aer (genitive aeros) "air" (related to aenai "to blow, breathe"), of unknown origin, possibly from a base *awer- and thus related to aeirein "to raise" and arteria "windpipe, artery" (see aorta) on notion of "lifting, that which rises." In Homer mostly "thick air, mist;" later "air" as one of the four elements.
Words for "air" in Indo-European languages tend to be associated with wind, brightness, sky. In English, air Replaced native lyft, luft (see loft (n.)). To be in the air "in general awareness" is from 1875; up in the air "uncertain, doubtful" is from 1752. To build castles in the air is from 1590s (in 17c. English had airmonger "one preoccupied with visionary projects"). Broadcasting sense (e.g. on the air) first recorded 1927. To give (someone) the air "dismiss" is from 1900. Air pollution is attested by 1870.
1590s, "manner, appearance" (e.g. an air of mystery); 1650s, "assumed manner, affected appearance" (especially in phrase put on airs, 1781), from French air "look, appearance, mien, bearing, tone" (Old French aire "reality, essence, nature, descent, extraction," 12c.; cf. debonair), from Latin ager "place, field" (see acre) on notion of "place of origin."
But some French sources connect this Old French word with the source of air (n.1), and it also is possible these senses in English developed from or were influenced by air (n.1); cf. sense development of atmosphere and Latin spiritus "breath, breeze," also "high spirit, pride," and the extended senses of anima.
"melody, tune," 1580s, from Italian aria (see aria).
A colorless, odorless, tasteless, gaseous mixture, approximately 78 percent nitrogen and approximately 21 percent oxygen with lesser amounts of argon, carbon dioxide, hydrogen, neon, helium, and other gases.
This mixture, with varying amounts of moisture and particulate matter, enveloping Earth; the atmosphere.
Any of various respiratory gases. No longer in technical use.
The colorless, odorless, tasteless mixture of gases that surrounds the Earth. Air consists of about 78 percent nitrogen and 21 percent oxygen, with the remaining part made up mainly of argon, carbon dioxide, neon, helium, methane, and krypton in decreasing order of volume. Air also contains varying amounts of water vapor, particulate matter such as dust and soot, and chemical pollutants.
the atmosphere, as opposed to the higher regions of the sky (1 Thess. 4:17; Rev. 9:2; 16:17). This word occurs once as the rendering of the Hebrew _ruah_ (Job 41:16); elsewhere it is the rendering of _shamaiyim_, usually translated "heavens." The expression "to speak into the air" (1 Cor. 14:9) is a proverb denoting to speak in vain, as to "beat the air" (1 Cor. 9:26) denotes to labour in vain.