Arris n. (Arch.) The sharp edge or salient angle formed by two surfaces meeting each other, whether plane or curved; applied particularly to the edges in moldings, and to the raised edges which separate the flutings in a Doric column. Arris fillet, a triangular piece of wood used to raise the slates of a roof against a chimney or wall, to throw off the rain.
Arris gutter, a gutter of a V form fixed to the eaves of a building.
