bossage

Century Dictionary and Cyclopedia

1. n. In building: A stone which projects beyond the face of the adjacent work, and is laid rough, to be afterward carved into some ornamental or significant form.
2. n. Rustic work, consisting of stones which advance beyond the face of the building, with indentures or channels left in the joinings: used chiefly upon projecting corners. The cavities are sometimes round and sometimes beveled or in a diamond form, sometimes inclosed with a cavetto and sometimes with a listel. Also called rustic quoins.

Wiktionary

1. n. architecture A rough, unfinished stone block, which is left projecting from the wall of a building to be later sculpted.

GNU Webster's 1913

1. n. (Arch.) A stone in a building, left rough and projecting, to be afterward carved into shape.
2. n. (Arch.) Rustic work, consisting of stones which seem to advance beyond the level of the building, by reason of indentures or channels left in the joinings.