Early 18th century: from Italian, from Latin aer 'air'.

• air from Middle English:

  1 The main modern sense of air, ‘the invisible gaseous substance surrounding the earth’ entered English via Old French and Latin from Greek aēr. Aerial (late 16th century), meaning ‘a rod or wire by which signals are transmitted or received’ and ‘existing or happening in the air’, comes from the same source, along with the Italian word aria (early 18th century). Aerobic (late 19th century) is from aēr combined with Greek bios ‘live’.

  2 The senses of air ‘an impression or manner’ and ‘a condescending manner’ (as in she gave herself airs) are probably from a completely different word, Old French aire ‘site, disposition’, which derives from Latin ager ‘field’, the root of English words such as agriculture (Late Middle English). Airy-fairy (mid 19th century) ‘impractical and foolishly idealistic’, was originally used to mean ‘delicate or light as a fairy’. The English poet Alfred, Lord Tennyson (1809–1892), in his poem ‘Lilian’ (1830), described the subject as ‘Airy, fairy Lilian, Flitting, fairy Lilian’. See also gas