[ep-uh-sahy-kloid] 
| a curve generated by the motion of a point on the circumference of a circle that rolls externally, without slipping, on a fixed circle. Equation: x = (a + b) cos(θ) − b cos[(a + b)θ/b] and y = (a + b) sin(θ) − b sin[(a + b)θ/b]. |
ep·i·cy·cloid (ěp'ĭ-sī'kloid')  (click for larger image in new window) n. The curve described by a point on the circumference of a circle as the circle rolls on the outside of the circumference of a second, fixed circle. ep'i·cy·cloid'al (-kloid'l) adj. |
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