1870 in spiritualism, "subtle emanation around living beings;" earlier "characteristic impression" made by a personality (1859), earlier still "an aroma or subtle emanation" (1732). Also used in some mystical sense in Swedenborgian writings (by 1847). All from Latin aura "breeze, wind, the upper air," from Greek aura "breath, cool breeze, air in motion," from PIE *aur-, from root *wer- (1) "to raise, lift, hold suspended." The word was used in the classical literal sense in Middle English, "gentle breeze" (late 14c.). The modern uses all are figurative. In Latin and Greek, the metaphoric uses were in reference to changeful events, popular favor.

"violent or tempestuous windstorm," late 15c. (Caxton), obsolete from 18c., from French orage "a storm," from Vulgar Latin *auraticum, from Latin aura "breeze, wind" (see aura (n.)). Related: Oragious.

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."

1844, "pertaining to the ear," from Latin auris "the ear as the organ of hearing" (see ear (n.1)) + -al (1). Meaning "received or perceived by ear" is attested by 1860. Related: Aurally.

1796 in reference to members of a secret politico-religious society founded 1795 in Belfast to promote Protestant power in Northern Ireland, named for William of Orange (who became King William III of England and triumphed in Ireland at the head of a Protestant army at the Battle of the Boyne), of the German House of Nassau. His cousins and their descendants constitute the royal line of Holland.

The name is from the town of Orange on the Rhone in France, which became part of the Nassau principality in 1530. Its Roman name was Arausio, which is said in 19c. sources to be from aura "a breeze" and a reference to the north winds which rush down the valley, but perhaps this is folk etymology of a Celtic word. The name subsequently was corrupted to Auranche, then Orange.

The town has no obvious association with the fruit other than being on the road from Marseilles to Paris, along which masses of oranges were transported to northern France and beyond. In this roundabout way the political/religious movement of Northern Irish Protestantism acquired an association with the color orange, the Irish national flag acquired its orange band, and Syracuse University in New York state acquired its "Otto the Orange" mascot.