Origin: Classical

Apparently originally from Classical Latin Ariānus, from Ariāna, probably after German Arier, arisch and subsequently reinforced by related Sanskrit आर्य (ā́rya, “noble; noble one”) and + -n. The Sanskrit word is from Proto-Indo-Iranian *áryas (the original Indo-Iranian autonym). Borrowed into English in the 19th century, at first as a term for the Indo-Iranian languages, and later partly extended to the Indo-European languages and peoples following a theory by Friedrich Schlegel that connected the Indo-Iranian words arya/ā́rya with German Ehre (“honor”) and some older Germanic names, thus assuming that it was the original Indo-European autonym meaning "the honorable people". The original meaning of the Indo-Iranian autonym and its possible Indo-European origin/cognates are disputed (see the Wikipedia article for further details). The same Proto-Indo-Iranian root is the ultimate source of the country name Iran.

Etymology: Wiktionary (CC-BY-SA)