Cy"cloid (s?"kloid), n. [Cyclo-
+ -oid: cf. F. cycloïde.] (Geom.)
A curve generated by a point in the plane of a circle when
the circle is rolled along a straight line, keeping always in the
same plane.
&fist; The common cycloid is the curve described when
the generating point (p) is on the circumference of the
generating circle; the curtate cycloid, when that point
lies without the circumference; the prolate or
inflected cycloid, when the generating point (p)
lies within that circumference.
Cy"cloid, a. (Zoöl.)
Of or pertaining to the Cycloidei.
Cycloid scale (Zoöl.), a
fish scale which is thin and shows concentric lines of growth,
without serrations on the margin.
Cy"cloid, n. (Zoöl.)
One of the Cycloidei.