"cause to mix with carbonic acid or other gas," 1794 (implied in aerated), from aer/aër (used in old science for specific kinds of air, a sense later given to gas (n.1)), from Latin aer (see air (n.1)) + verbal suffix -ate (2). Meaning "expose to air" is from 1799, probably a back-formation from aeration. Related: Aerating.
Proto-Indo-European root meaning "to raise, lift, hold suspended."
It forms all or part of: aerate; aeration; aerial; aero-; aerobics; aerophyte; aerosol; air (n.1) "invisible gases that surround the earth;" airy; aorta; anaerobic; aria; arterial; arterio-; arteriosclerosis; arteriole; artery; aura; malaria; meteor.
It is the hypothetical source of/evidence for its existence is provided by: Greek aerein "to lift, raise up;" Lithuanian svarus "heavy," sverti "to lift, weigh;" Old English swar, Old Norse svarr, Old High German swar, German schwer "heavy."
digraph in certain Greek or Latin words; it developed in later Latin where classical Latin used separate letters. The Latin digraph also was used to transliterate Greek -ai- (as in aegis). When Latinate words flooded English in the 16c. it came with them, but as an etymological device only, and it was pronounced simply "e" and eventually reduced to that letter in writing (as in eon, Egypt) in most cases, excepting (until recently) proper names (Cæsar, Æneas, Æsculapius, Æsop). When divided and representing two syllables (aerate, aerial) it sometimes is written aë.