torus

noun

to·​rus ˈtȯr-əs 

plural tori ˈtȯr-ˌī  -ˌē 

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

And since opposite sides of the box are identical — remember, the box is our 3D torus stand-in — those two circles will be identical as well. —Steve Nadis, Quanta Magazine, 27 Jan. 2025

In this case, there are multiple ways for a light ray to travel around the surface of the torus and return to the same point. —Steve Nadis, Quanta Magazine, 27 Jan. 2025

She’s also discovered the Big Ring, a torus of galaxies about 1.3 billion light-years across and four billion around. —Sarah Scoles, Scientific American, 1 Jan. 2025

One [Gardner puzzle book] had a picture on the cover of what mathematicians call a torus, the shape of a doughnut or a bagel. —Sarah Lewin Frasier, Scientific American, 29 Oct. 2024

Word History

Etymology

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

First Known Use

1563, in the meaning defined at sense 1

Rhymes for torus

• chloris
• chorus
• horus
• lores
• morrice
• morus
• orris
• porous
• porus
• authorise
• clitoris
• liquorice

Medical Definition

torus

noun

to·​rus ˈtōr-əs, ˈtȯr- 

plural tori ˈtō(ə)r-ˌī  ˈtȯ(ə)r- 

-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