in architecture, a term used for any stone that has a projection, and is laid rough in a building, to be afterwards carved into mouldings, capitals, coats of arms, &c. Bossage is also that which is otherwise called rustic work; and consists of stones which advance beyond the naked, or level of the building, by reason of indentures or channels left in the joinings. These are chiefly used in the corners of edifices, and thence called rustic quoins. The cavities or indentures are sometimes round, sometimes chain-framed, or bevelled, sometimes in a diamond form, sometimes inclosed with a cavetto, and sometimes with a listel.