Arris \Ar"ris\, n. [OF. areste, F. ar[^e]te, fr. L. arista the top or beard of an ear of grain, the bone of a fish.]

(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. --P. Cyc.

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. --Gwilt.

Arris gutter, a gutter of a V form fixed to the eaves of a building. --Gwilt.

Source: Webster's Revised Unabridged Dictionary (1913)