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

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

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

This structure forms the inner portion of the dusty torus and acts as the primary reservoir funneling material inward to feed the black hole, the study finds. —Sharmila Kuthunur, Space.com, 19 Jan. 2026

Each point on this torus represents one possible state of the pendulum; paths on the torus represent the trajectories the pendulum might follow through space. —Paulina Rowińska, Wired News, 28 Dec. 2025

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