Meaning

adjective characterized by lightness and insubstantiality; as impalpable or intangible as air; - Thomas Carlyle

adjective of or containing or dissolved in ether

adjective of heaven or the spirit

originFrom Latin aetherius (“of or pertaining to the ether, the sky, Heaven or the air or upper air”), from Ancient Greek αἰθέριος (aithérios, “of or pertaining to the upper air”). By surface analysis, ether + -ial.

Etymology from Wiktionary, CC BY-SA 3.0