[tawr-oid, tohr-]
noun Geometry.
  1. a surface generated by the revolution of any closed plane curve or contour about an axis lying in its plane.
  2. the solid enclosed by such a surface.

Origin of toroid

First recorded in 1895–1900; tor(us) + -oid Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for toroid


  1. geometry a surface generated by rotating a closed plane curve about a coplanar line that does not intersect the curve
  2. the solid enclosed by such a surfaceSee also torus
Derived Formstoroidal, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

toroid in Science


  1. A surface generated by rotating a closed curve about an axis that is in the same plane as the curve but does not intersect it.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.