meirg

rust, Irish meirg, Old Irish meirg, meirc, Breton mergl: *mergi-, "red, dark"; English murk, Anglo-Saxon mirce, Norse myrkr (cf. Gaelic dearg and English dark). Ernault compares Greek $$Gmárgos, senseless; and it has been joined to Old Welsh mergid, debilitas, Old Breton mergidhehan, evanesco, root mar, mer, fade, die.