1. a caplike part or thing; cover, or top. 2. An upper limit set on a budget or cost; a ceiling. 3. A trim tile with a convex radius on one edge; used for finishing the top of a wainscot or for turning an outside corner, a bullnose. 4. The upper member of a column, pilaster, door, cornice molding, and the like. 5. A female pipe fitting, solid at one end; used to close off the end of a piece of pipe. 6. Masonry units laid on top of finished masonry wall or pier. 7. Flashing for tops of parapet walls.