buttress

BUT'TRESS, n. [This word appears to be composed of but,end, and truss, or some word of that family.]

1. A prop; a wall or abutment built archwise, serving to support another wall on the outside, when very high or loaded with a heavy superstructure.

2. Any prop or support.

BUT'TRESS, v.t. To support by a buttress; to prop.