in architecture, a kind of dye cut diagonal-wise, after the manner of a flight of a stair case, serving at bottom to support columns in a level, and at top to correct the inclination of an entablature supporting a vault.

Coin is also used for a solid angle composed of two surfaces inclined towards each other, whether that angle be exterior, as the coin of a wall, a tree, &c. or interior, as the coin of a chamber or chimney. See QUOIN.