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 duo have been cautious in their classification, allowing for the possibility that a torus of material could be behind the observations. —Nola Taylor Tillman, Space.com, 10 Sep. 2025

Ejecta from its innermost large, volcano-rich moon, Io, populates this inner magnetosphere with sulfur dioxide gas, where the magnetic field forces this material to co-rotate with Jupiter itself in a torus-like shape. —Ethan Siegel, Big Think, 3 Sep. 2025

The latest observations provide a wide wavelength spectrum look at the Butterfly Nebula’s dense band of gas known as a torus. —Andrew Paul, Popular Science, 27 Aug. 2025

This is a puffy torus of older stars moving at high velocities above and below the main flat plane of the Milky Way—which is where our sun serenely orbits. —Jonathan O'Callaghan, Scientific American, 16 July 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