There are different hypotheses on the origin of this word. Some propose to derive it from Proto-Baltic *air-, from Proto-Indo-European *ey-, *oy- (“pole, post”) with an extra r. Others derive it from the same stem as Latvian vairīt “to avoid; to dodge,” with loss of the initial v. Others yet consider it an old borrowing from a Germanic language (cf. Old Norse ár, Old English ār, English oar, all from Proto-Germanic *airō), possibly mediated by Livonian āiraz (from Proto-Finnic *airo). Cognates include Lithuanian ai̇̃rė.