A nickname given to S. Amras to distinguish him from his twin brother Amrod, since they were both known by the name Ambarussa “Top-russet” for their red hair (VT41/10). The second element is russa “red-haired”, and the initial element atya is probably intended to mean “second”, but elsewhere the Quenya words for “second” are given as (archaic) †tatya and (modern) attëa (WJ/380, VT42/25).