Ross (Ros in Scottish Gaelic) is a region of Scotland and a former mormaerdom, earldom, sheriffdom and county. The name Ross allegedly derives from a Gaelic word meaning "headland", perhaps a reference to the Black Isle. Another possible origin is the Norse word for Orkney – Hrossey – meaning horse island; the area once belonged to the Norse earldom of Orkney. Ross is a historical comital region, perhaps predating the Mormaerdom of Ross.