[ troh-koid ]
/ ˈtroʊ kɔɪd /


Geometry. a curve traced by a point on a radius or an extension of the radius of a circle that rolls, without slipping, on a curve, another circle, or a straight line. Equation: x = b sin θ, y = ab cos θ.


rotating on an axis, as a wheel.

Origin of trochoid

First recorded in 1695–1705, trochoid is from the Greek word trochoeidḗs round like a wheel. See troche, -oid


tro·choi·dal, adjectivetro·choi·dal·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for trochoid

  • Then any point in the circumference of the half-crown will move through a curve called a ‘trochoid.’

    Boating|W. B. Woodgate

British Dictionary definitions for trochoid

/ (ˈtrəʊkɔɪd) /


the curve described by a fixed point on the radius or extended radius of a circle as the circle rolls along a straight line

adjective Also: trochoidal

rotating or capable of rotating about a central axis
anatomy (of a structure or part) resembling or functioning as a pivot or pulley

Derived forms of trochoid

trochoidally, adverb

Word Origin for trochoid

C18: from Greek trokhoeidēs circular, from trokhos wheel
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

Medicine definitions for trochoid

[ trōkoid′, trŏkoid′ ]


Capable of or exhibiting rotation about a central axis.
Permitting rotation, as a pivot.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.