Definify.com
Webster 1913 Edition
Arris
Ar′ris
,Noun.
[OF.
areste
, F. arête
, 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.