torusto·rus (tôr??s)n. pl. to·ri (tôr??) 1. Architecture A large convex molding, semicircular in cross section, located at the base of a classical column.2. Anatomy A bulging or rounded projection or swelling.3. Botany a. The receptacle of a flower.b. A thickened area in the middle of the membrane that connects the pits of tracheids in conifers and certain other gymnosperms.4. Mathematics A toroid generated by a circle; a surface having the shape of a doughnut. Also called tore2.[Latin, bulge, knot, torus.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.torus (?t??r?s) n, pl -ri (-ra?) 1. (Architecture) Also called: tore a large convex moulding approximately semicircular in cross section, esp one used on the base of a classical column2. (Mathematics) geometry a ring-shaped surface generated by rotating a circle about a coplanar line that does not intersect the circle. Area: 4?2Rr; volume: 2?2Rr2, where r is the radius of the circle and R is the distance from the line to the centre of the circle3. (Botany) botany another name for receptacle24. (Anatomy) anatomy a ridge, fold, or similar linear elevation5. (Celestial Objects) astronomy a dense ring of gas and dust which surrounds a dying star, containing most of the star’s ejected gas[C16: from Latin: a swelling, of obscure origin]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014to?rus (?t?r ?s, ?to?r-) n., pl. to?ri (?t?r a?, ?to?r a?) 1. a large convex molding, semicircular in profile, commonly forming the lowest member of the base of a column, directly above the plinth. 2. a. a doughnut-shaped surface generated by the revolution of a conic, esp. a circle, about an exterior line lying in its plane. b. the solid enclosed by such a surface. 3. Bot. the receptacle of a flower. 4. Anat. a rounded ridge; a protuberant part. [1555?65;