torus
Americannoun
plural
tori-
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.
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Geometry.
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Rarely a doughnut-shaped surface generated by the revolution of a conic section, especially a circle, about an exterior line lying in its plane.
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the solid enclosed by such a surface.
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Botany.
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the receptacle of a flower.
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a thickening of the wall membrane in the bordered pits occurring in the tracheid cells of the wood of many conifers.
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Anatomy. a rounded ridge; a protuberant part.
noun
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Also called: tore. a large convex moulding approximately semicircular in cross section, esp one used on the base of a classical column
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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
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botany another name for receptacle
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anatomy a ridge, fold, or similar linear elevation
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astronomy a dense ring of gas and dust which surrounds a dying star, containing most of the star's ejected gas
plural
tori-
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.
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The torus-shaped apparatus that contains plasma in nuclear fusion reactors.
Etymology
Origin of torus
First recorded in 1555–65; from Latin: literally, “strand, thong, raised ridge”
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Bouma's next goal is to determine where the material in the torus originates, whether it comes from the star itself or from an external source.
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
One eruption could push more ionized gas into the torus.
From New York Times • Jan. 25, 2023
Or it could mean that the torus was rapidly diffusing in response to the intense eruption.
From New York Times • Jan. 25, 2023
A malfunctioning gauge in the torus had shown a sudden drop in pressure.
From "Meltdown" by Deirdre Langeland
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.