Of uncertain origin and meaning. Theories include a derivation from Latvian airene "ryegrass, darnel", a contracted form of Airisa and a modern coinage with no set meaning.
From Japanese 亜 (a) meaning "second, Asia", 伊 (i) meaning "Iraq, Iran" combined with 羅 (ra) meaning "lightweight fabric". Other kanji combinations are possible.
The name comes directly from the Lithuanian word Airijos (Irish), perhaps inspired by Erin or a borrowing from the Latvian Aira, which has a different etymology.