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[tawr-uh s, tohr-] /ˈtɔr əs, ˈtoʊr-/
noun, plural tori
[tawr-ahy, tohr-ahy] /ˈtɔr aɪ, ˈtoʊr aɪ/ (Show IPA)
Architecture. a large convex molding, more or less semicircular in profile, commonly forming the lowest molding of the base of a column, directly above the plinth, sometimes occurring as one of a pair separated by a scotia and fillets. and column.
  1. a doughnut-shaped surface generated by the revolution of a conic, especially a circle, about an exterior line lying in its plane.
  2. the solid enclosed by such a surface.
  1. the receptacle of a flower.
  2. a thickening of the wall membrane in the bordered pits occurring in the tracheid cells of the wood of many conifers.
Anatomy. a rounded ridge; a protuberant part.
Origin of torus
1555-65; < Latin: literally, strand, thong, raised ridge Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for torus


noun (pl) -ri (-raɪ)
Also called tore. a large convex moulding approximately semicircular in cross section, esp one used on the base of a classical column
(geometry) a ring-shaped surface generated by rotating a circle about a coplanar line that does not intersect the circle. Area: 4π²Rr; volume: 2π²Rr², where r is the radius of the circle and R is the distance from the line to the centre of the circle
(botany) another name for receptacle (sense 2)
(anatomy) a ridge, fold, or similar linear elevation
(astronomy) a dense ring of gas and dust which surrounds a dying star, containing most of the star's ejected gas
Word Origin
C16: from Latin: a swelling, of obscure origin
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for torus

1560s, from Latin torus "a swelling, bulge, knot; cushion, couch."

Online Etymology Dictionary, © 2010 Douglas Harper
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torus in Medicine

torus to·rus (tôr'əs)
n. pl. to·ri (tôr'ī)
A bulging or rounded projection or swelling, such as is caused by a bone or muscle.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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torus in Science
Plural tori (tôr'ī)
  1. A surface generated by rotating a circle about an axis that is in the same plane as the circle but does not intersect it. A torus resembles a donut and is a subtype of toroid.

  2. The torus-shaped apparatus that contains plasma in nuclear fusion reactors.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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