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 (trō′koid′, trŏk′oid′)
A curve traced by a point on or connected with a circle as the circle rolls along a fixed straight line.
adj. also tro·choi·dal (trō-koid′l, trŏk-oid′l)
1. Capable of or exhibiting rotation about a central axis.
2. Permitting rotation, as a pulley or pivot.

[Greek trokhoeidēs, wheellike : trokhos, wheel; see trochee + -oeidēs, -oid.]

tro·choi′dal·ly adv.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Mathematics) the curve described by a fixed point on the radius or extended radius of a circle as the circle rolls along a straight line
1. (Mathematics) rotating or capable of rotating about a central axis
2. (Anatomy) anatomy (of a structure or part) resembling or functioning as a pivot or pulley
[C18: from Greek trokhoeidēs circular, from trokhos wheel]
troˈchoidally adv
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈtroʊ kɔɪd)

1. 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.
2. rotating on an axis, as a wheel.
[1695–1705; < Greek trochoeidḗs round like a wheel. See troche, -oid]
tro•choi′dal, adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
Called 'App Anatomia Humana', the application (Figure 1) is divided in ten tabs: introduction, the joints, conceptual map, morphological types, condylar images, spheroideal images, ginglymus images, plane images, saddle images, and trochoid images.
Knee joint has the feature of both ginglymus and trochoid joint [21].
DRUJ is a diarthrodial trochoid synovial joint relatively new in evolution, evolved from the primitive pectoral fin of early fish to the bipedal primate wrist to its current form in human wrist.
Gerstner showed that the motion of each water particle is a circle of radius r around a fixed point, giving a wave profile that can be described by a mathematical function called trochoid.
If, in addition, the initial velocity of the particle has no component along the electric field, then the general trajectory of the particle is a trochoid. Four special cases are, (1) If this component is positive, the trajectory is a curtate cycloid; (2) If this component is negative, the trajectory is a prolate cycloid; (3) If this component is zero, the trajectory is a cycloid; and (4) If this component is equal to the electromagnetic drift velocity, the trajectory is a straight line; both the curvature and torsion of the path are zeros.
Oil flow trochoid (OFT) can denote the frictional stress approximately, through the analysis of oil flow pattern; the whole flow around bodies of revolution characteristic can be obtained.
The geometry of the gear drive and gear driving is obtained using mathematical formulations for a real case of manufacturing, including trochoid form at the tooth foot region.
[P.sub.F] = curvature radius of tooth trochoid at the critical section
Then the observer sees the electron moving on a curve which is a cycloid or trochoid, see Fig.
The ankle, or talocrural joint, is a trochoid synovial joint.
Trochoid Joints that operate with a pulley-type function, such as the atlas/axial joint.