[ Gr. ky`klos circle, wheel. ] A combining form meaning circular, of a circle or wheel. [ 1913 Webster ]

a. [ Cyclo- + branchiate. ] (Zool) Having the gills around the margin of the body, as certain limpets. [ 1913 Webster ]

a. (Zool.) Of or pertaining to the Cycloganoidei. [ 1913 Webster ]

n. (Zool.) One of the Cycloganoidei. [ 1913 Webster ]

‖n. pl. [ NL., fr. Gr. ky`klos circle + NL. ganoidei. See Ganoid. ] (Zool.) An order of ganoid fishes, having cycloid scales. The bowfin (Amia calva) is a living example. [ 1913 Webster ]

n. [ Cyclo- + -graph. ] See Arcograph. [ 1913 Webster ]

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. [ 1913 Webster ]

☞ 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. [ 1913 Webster ]

a. (Zool.) Of or pertaining to the Cycloidei. [ 1913 Webster ]

Cycloid scale (Zool.), a fish scale which is thin and shows concentric lines of growth, without serrations on the margin. [ 1913 Webster ]

n. (Zool.) One of the Cycloidei. [ 1913 Webster ]

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 ]