*arwaz^²

Probably from pre-Germanic *h₂erwós, an adjective based on the u-stem *h₂er-u- from Proto-Indo-European root *h₂er-, with a semantic development ‘properly fitted, prepared’ > ‘ready’ and thence ‘quick, prompt’. This analysis is supported especially by Tocharian A ārwar and Tocharian B ārwer, although the precise derivation of the Tocharian forms is disputed (Adams 2013: 56–57; Kroonen 2013: s.v. *arwa-; Pronk 2013: 294–96; Pronk 2019: 130). Pronk proposes that the Germanic adjective directly continues *h₂er-u-o- and cautions against treating Avestan 𐬀𐬎𐬭𐬎𐬎𐬀𐬧𐬙 (aᵘruuaṇt-) and 𐬀𐬎𐬭𐬎𐬎𐬀 (aᵘruua-) as secure cognates: the Iranian words may instead be inner-Indo-Iranian derivatives of *h₁er- or *h₃er-. Derivation from *h₂er- is preferable, but the wider Indo-European comparison remains uncertain. See also *garwaz.