*aurijaz

Traditionally regarded as borrowed from Latin aureus, whence Old Norse eyrir, plural aurar (de Vries 1977: 108). Aureus is derived from aurum, from Proto-Italic *auso- < Proto-Indo-European *h₂e-h₂us-o- (de Vaan 2008: 63). This derivation is disputed: the singular and plural reflect different stem formations (ija-stem eyrir beside apparently a-stem aurar), and the Scandinavian ounce of 26.8 g corresponds closely to the Roman uncia, not to the much lighter aureus (Ruthström 1993: 93–98). Ruthström instead derives aurar from an old Germanic r-extension related to *audaz, with eyrir formed secondarily from it, but acknowledges that the proposed semantic development remains hypothetical (Ruthström 1993: 100–101, 117–18).