farrier: [16] Etymologically, a farrier is a ‘worker in iron’. The word comes via Old French ferrier from Latin ferrārius, a derivative of ferum. This meant literally ‘iron’ (it is the source of English ferrous [19], and may well have been borrowed from a Semitic source), and already in classical times was being applied metaphorically to implements made from iron, particularly ‘swords’. Its use for ‘horseshoe’, on which the meaning of farrier is based, is a medieval Latin development. => ferrous
