ferrier

a farrier; a blacksmith; a small mound, heap, or hill composed of the remnants or by-products (slag/dross/scoria) of an ancient iron forge or bloomery, especially from the late Iron age and Gallo-Roman era in France

Taken from the Old French ferrier, from Latin ferrārius, from ferrum (“iron”); alternatively, fer + -ier. Only used in historical contexts in modern French.