*arhwō

Probably ultimately from a European non-Indo-European substrate word-family. Kroonen (2013: 34) tentatively derives the Northwest Germanic forms from pre-Germanic *h₂érk-uh₂, ~ *h₂erk-wéh₂-s, a feminine *uh₂-stem, yielding Early Germanic *arhū ~ *arhwōz, yielding Old English earh beside Northumbrian arwe and Old Norse ǫr ~ ǫrvar, though the precise post-Verner development remains uncertain (de Vaan & Kroonen 2016: 314–15; Ringe 2017: 133). De Vaan (2008: 52) derives cognate Latin arcus from Proto-Italic *arkuo-/*arkʷo-. Ancient Greek ἄρκευθος (árkeuthos), Cypriot ἄργετος (árgetos), and Proto-Slavic *orkyta have been compared through their association with wood used for bows, with the Germanic word initially meaning something like ‘that which comes with a bow’, but recent work treats these tree names as probable substrate material rather than regular inherited cognates (Kroonen 2024: 307–308; Matasović 2024: 57).