Likewise already in Hesychius omicron1283 and in a scholion on Nicander, Theriaca 5 (where the headword occurs; again, but in the plural, at 377); similarly, with the headword as o)rotu/pos, in other lexica (references at Photius omicron518 Theodoridis).
Also spelled o)reitu/pos and o)reotu/pos.