torus

noun pl. tori

1. Anat. any rounded projection or swelling
2. Archit. a large, convex molding used at the base of columns, etc., just above the plinth
3. Bot.
   1. receptacle (sense )
   2. a thick spot at the center of the pit membrane in bordered pits of xylem cells
4. Geom. a surface, or its enclosed solid, generated by the revolution of a conic about any line that is external to the conic but in the same plane, as a doughnut-shaped figure that is generated by a circle or an ellipse