airy (adj.)

late 14c., "of the air, containing air, made of air," from air (n.1) + -y (2). Meanings "breezy, exposed to the air, open to currents of air; lofty, high; light, buoyant; flimsy; flippant, jaunty, affectedly lofty; vain; unreal" all are attested by late 16c. From 1620s as "done in the air;" 1640s as "sprightly, light in movement;" 1660s as "visionary, speculative." Disparaging airy-fairy "unrealistic, fanciful" is attested from 1920 (earlier in a sense of "delicate or light as a fairy," which is how Tennyson used it in 1830).