torus

American  

[tawr-uhs] / ˈtɔr əs /

noun

tori plural

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.

2. Geometry.

   1. Rarely a doughnut-shaped surface generated by the revolution of a conic section, 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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torus British  

/ ˈtɔːrəs /

noun

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

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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torus Scientific  

/ tôr′əs /

tori plural

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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Other Word Forms

Noun Inflected Forms

• tori
  plural

Etymology

Origin of torus

First recorded in 1555–65; from Latin: literally, “strand, thong, raised ridge”

Example Sentences

These plasma clumps are carried along by the star's magnetic field, forming a doughnut shaped structure called a torus.

From Science Daily • Mar. 27, 2026

Iron located in the torus caused these dips as well, although through absorption of X-rays, rather than emission, because the material there is much cooler than in the disk.

From Science Daily • May 8, 2024

Or it could mean that the torus was rapidly diffusing in response to the intense eruption.

From New York Times • Jan. 25, 2023

The torus wasn’t as bright as it should have been.

From New York Times • Jan. 25, 2023

To do that, they would need to walk out onto the surface of the torus.

From "Meltdown" by Deirdre Langeland