a. Pertaining to, or resembling, a cycloid; as, the cycloidal space is the space contained between a cycloid and its base. [ 1913 Webster ]

Cycloidal engine. See Geometric lathe. [ 1913 Webster ]

a. Pertaining to the epicycloid, or having its properties. [ 1913 Webster ]

Epicycloidal wheel, a device for producing straight-line motion from circular motion, on the principle that a pin fastened in the periphery of a gear wheel will describe a straight line when the wheel rolls around inside a fixed internal gear of twice its diameter. [ 1913 Webster ]