bowtell

1. A plain, convex molding, usually three-quarters of a circle in section.
2. A torus or round molding.
3. The shaft of a clustered pillar.
4. A roll molding.
5. A quarter round or ovolo.

Also called boltel, bottle, boultel, boultin, a plain moulding with a convex section, such as a roll-moulding, ovolo, or torus. It is larger than an astragal or bead, and is sometimes used to describe the colonnettes or shafts of medieval clustered piers.