Definition of "torus" [to•rus]

• Architecture A large convex molding, semicircular in cross section, located at the base of a classical column. (noun)
• Anatomy A bulging or rounded projection or swelling. (noun)
• Botany The receptacle of a flower. (noun)
• Mathematics A toroid generated by a circle; a surface having the shape of a doughnut. Also called tore2. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The only moulding known is the clustered torus (_torus_ = a convex moulding of semicircular profile), which resembles a bundle of reeds tied together with cords or ribbons."
• "As a practical matter, to make the ship Climb, or go null, Engineering pumps massive energies into the Climber's torus, which is a closed hyper drive."
• "I say 'of its stalk,' -- that is to say, of the part of the stalk immediately sustaining the seed, commonly called the torus, and expanding into the calyx."