From Proto-Austronesian *(i-)kita.
From Proto-Baltic *aitā, from Proto-Indo-European *ey-, *oy- (“to go”) (cf. iet) with an extra syllable tā. The original meaning was thus “goer, one that goes (around),” a common source of words for “sheep” (cf. Russian, Belarusian, Ukrainian баран (baran), a borrowing from Proto-Turkic *baran (“one that goes”)). An alternative theory, which derives aita from the diminutive avitiņa of dated avs (“sheep”) is less likely to be correct, since the avi > ai change would be irregular. Cognates include Lithuanian áita (feminine), áitas (“one who walks around a lot; restless person”) (masculine), Old Prussian aytegenis (“small (quick, restless) woodpecker”), Russian dialectal етенька (jetenʹka, “name used to call sheep”) (from *ěta- < *ait-), Hittite 𒇻 (iyant-, “sheep”) (lit. “goer, one that goes”).
Borrowed from Basque aita.
From Proto-Finnic *aita.