torus

[ tawr-uhs ]

noun

, plural to·ri [tawr, -ahy].

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.

torus

/ ˈtɔːrəs /

noun

1. Also calledtore 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

torus

/ tôr′əs /

, 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.

Word History and Origins

Origin of torus¹

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

Word History and Origins

Origin of torus¹

C16: from Latin: a swelling, of obscure origin

Example Sentences

A puffy donut-shaped cloud of material called a torus surrounds the accretion disk.

From Science Daily

As with most active galaxies, NGC 4945's black hole and disk are shrouded by a dense cloud of dust called a torus, which blocks some of that light.

From Science Daily

Kelly, who gained popularity in 2016 with her debut album “Unbreakable Smile,” has been promoting her upcoming EP “tori” on social media.

From Los Angeles Times

One of the most popular is the tokamak, a device that creates a magnetic field to contain the burning plasma generated by a fusion reaction in a doughnut-shaped ‘torus’.

From Scientific American

One eruption could push more ionized gas into the torus.

From New York Times