(n.) A round, convex molding.

abacus acanthus annulet apophyge architrave astragal beading beak bell billet boss capstone cartouche cavetto cima cinquefoil conge console coping corbel cornice crown cusp cyma dentil drip drop fascia fillet finial foil fret frontispiece head header headpiece keystone lintel listel molding ovolo patera pendant quatrefoil reed sconce splay taenia terminal torus treenail trefoil tympanum volute