torus

noun

to·​rus ˈtȯr-əs How to pronounce torus (audio)
plural tori ˈtȯr-ˌī How to pronounce torus (audio) -ˌē How to pronounce torus (audio)
1
: a large molding of convex profile commonly occurring as the lowest molding in the base of a column
2
: the thickening of a membrane closing a wood-cell pit (as of gymnosperm tracheids) having the secondary cell wall arched over the pit cavity
3
: a doughnut-shaped surface generated by a circle rotated about an axis in its plane that does not intersect the circle
broadly : toroid
4
: a smooth rounded anatomical protuberance (such as a bony ridge on the skull)

Examples of torus in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Which meant that while the curvature lines might live on planes and spheres, the overall surface wouldn’t be a torus. — Elise Cutts, Quanta Magazine, 20 Jan. 2026 The surrounding torus is formed from a semicrystalline polymer that’s coated with beryllium using Physical Vapor Deposition. — Mark Sparrow, Forbes.com, 21 Jan. 2026 Discovered in the 1970s, WOH G64 has always appeared to be a red supergiant star surrounded by a ring, or torus, of dense dust. — Robert Lea, Space.com, 26 Feb. 2026 The radiation emanating from an AGN’s accretion disk also appears to dictate the size and orientation of its obscuring torus. — Emma Gometz, Scientific American, 16 June 2026 See All Example Sentences for torus

Word History

Etymology

New Latin, from Latin, protuberance, bulge, torus molding

First Known Use

1563, in the meaning defined at sense 1

Time Traveler
The first known use of torus was in 1563

Rhymes for torus

See All Rhymes for torus

Browse Nearby Words

Toruń
torus
Tory
See all Nearby Words

Cite this Entry

“Torus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/torus. Accessed 7 Jul. 2026.

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Medical Definition

torus

noun
to·​rus ˈtōr-əs, ˈtȯr- How to pronounce torus (audio)
plural tori ˈtō(ə)r-ˌī How to pronounce torus (audio) ˈtȯ(ə)r- How to pronounce torus (audio)
-ˌē
1
: a doughnut-shaped surface generated by a circle rotated about an axis in its plane that does not intersect the circle
2
: a smooth rounded anatomical protuberance (as a bony ridge on the skull)
a supraorbital torus
Last Updated: - Updated example sentences
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