In Old Norse, ǫ́ss (or áss, ás, plural æsir; feminine ásynja, plural ásynjur) is a member of the principal pantheon in Norse religion. This pantheon includes Odin, Frigg, Thor, Baldr and Týr. The second pantheon comprises the Vanir. In Norse mythology, the two pantheons wage the Æsir–Vanir War, which results in a unified pantheon.
The cognate term in Old English is ōs (plural ēse) denoting a deity in Anglo-Saxon paganism. The Old High German is ans, plural ensî. The Gothic language had ans- (based only on Jordanes who glossed anses with uncertain meaning, possibly 'demi-god' and presumably a Latinized form of actual plural *anseis). The reconstructed Proto-Germanic form is *ansuz (plural *ansiwiz). The ansuz rune, ᚫ, was named after the æsir.