Definition of torus in English:

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Pronunciation: /ˈtɔːrəs/

noun (plural tori /ˈtɔːrʌɪ/ or toruses)

1 Geometry A surface or solid formed by rotating a closed curve, especially a circle, about a line which lies in the same plane but does not intersect it (e.g. like a ring doughnut).
Example sentences
  • To be rigorous, the hole is not actually in the torus: the torus is the surface and the hole is in the space around the surface.
  • A small patch of a sphere or torus surface looks almost like a piece of a flat plane and has area rather than volume.
  • ‘In other words, each solution could be drawn on the surface of a torus,’ he notes.
1.1A ring-shaped object, especially a large ring-shaped chamber used in physical research.
Example sentences
  • Like tokamaks, their currently more advanced cousins, stellarators use magnetic fields to confine plasma in a torus for fusion reactions.
  • This remarkable device consists of a torus of alternating magnetic materials that are chosen so that the torus has a huge net spin - 10 22 aligned electron spins - yet produces no magnetic field.
  • By carefully accounting for the particles injected into the machine and for those exhausted in the pumping system we found a deficit, indicating that a large fraction of deuterium gets trapped in the walls and components inside the torus.
2 Architecture A large convex moulding, typically semicircular in cross section, especially as the lowest part of the base of a column.
Example sentences
  • One stand has a torus molding with red-painted triglyph and metopal sections, while a lower register has alternating black and white sections.
  • A long cylindrical bar of orange-painted steel evokes a tori (temple gate) and serves as a balustrade.
  • The gadrooned flattened torus moulding, shown on the shelf or footrest of the stand in the engraving also appears on the stretchers of the Blenheim stands.
3 Anatomy A ridge of bone or muscle: the maxillary torus
More example sentences
  • The supraorbital torus is lost in most modern humans, and ridging above the orbits in general is very reduced.
  • A torus, or ‘buckle,’ fracture of the distal radius is a common type of fracture in children.
  • In children, the most common injury is the torus fracture, which occurs with a fall onto an outstretched hand.
4 Botany The receptacle of a flower.


Mid 16th century (in sense 2): from Latin, literally 'swelling, bolster, round moulding'. The other senses date from the 19th century.

Words that rhyme with torus

brachiosaurus, brontosaurus, canorous, chorus, Epidaurus, giganotosaurus, Horus, megalosaurus, pelorus, porous, sorus, stegosaurus, Taurus, thesaurus, tyrannosaurus

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Line breaks: torus

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