BEVEL (from an O. Fr. word, cf. mod. biveau, a joiner's instrument), the inclination of one surface of a solid body to another; also, any angle other than a right angle, and particularly, in joinery, the angle to which a piece of timber has to be cut. The mechanic's instrument known as a bevel consists of a rule with two arms so jointed as to be adjustable to any angle. In heraldry, a bevel is an angular break in a line. Bevelment, as a term of crystallography, means the replacement of an edge of a crystal by two planes equally inclined to the adjacent planes. As an architectural term "bevel" is a sloped or canted edge given to a sill or horizontal course of stone, but is more frequently applied to the canted edges worked round the projecting bands of masonry which for decorative purposes are employed on the quoins of walls or windows and in some cases, with vertical joints, cover the whole wall. When the outer face of the stone band is left rough so that it forms what is known as rusticated masonry, the description would be bevelled and rusticated. The term is sometimes applied to the splaying of the edges of a window on the outside, but the wide expansion made inside in order to admit more light is known as a splay.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)