• synonyms


[tawr-uh s, tohr-]
noun, plural to·ri [tawr-ahy, tohr-ahy] /ˈtɔr aɪ, ˈtoʊr aɪ/.
  1. 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.
  2. Geometry.
    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.
  3. Botany.
    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.
  4. Anatomy. a rounded ridge; a protuberant part.
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Origin of torus

1555–65; < Latin: literally, strand, thong, raised ridge
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for torus

Historical Examples of torus

  • The lateral arcades have similar capitals but only one torus.

    Rheims and the Battles for its Possession


  • Thalamaflorous, with petals and stamens inserted on the torus or Thalamus.

  • A beautiful and early example of its use occurs on the torus of the Ionic columns of the Erectheum at Athens.

  • The Torus or Receptacle of the flower (237, Fig. 223) is the portion which belongs to the stem or axis.

  • At this time each pistil loosens from the torus and can be easily removed, especially if some animal touch the hooks.

    Seed Dispersal

    William J. Beal

British Dictionary definitions for torus


noun plural -ri (-raɪ)
  1. Also called: tore a large convex moulding approximately semicircular in cross section, esp one used on the base of a classical column
  2. geometry a ring-shaped surface generated by rotating a circle about a coplanar line that does not intersect the circle. Area: 4π² Rr; volume: 2π² Rr ², where r is the radius of the circle and R is the distance from the line to the centre of the circle
  3. botany another name for receptacle (def. 2)
  4. anatomy a ridge, fold, or similar linear elevation
  5. astronomy a dense ring of gas and dust which surrounds a dying star, containing most of the star's ejected gas
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Word Origin for torus

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

Word Origin and History for torus


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

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Online Etymology Dictionary, © 2010 Douglas Harper

torus in Medicine


n. pl. to•ri (tôrī)
  1. A bulging or rounded projection or swelling, such as is caused by a bone or muscle.
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The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

torus in Science


Plural tori (tôrī)
  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.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.