Meaning of trochoid

tro•choid

Pronunciation: (trō'koid), [key]
— n.
  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. Equation:= a&thgr; − b sin &thgr;, y = a − b cos &thgr;. x
—adj.
  1. rotating on an axis, as a wheel.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.