What does "cycloid" mean?

Cycloid: 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. Note: 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.

Additional senses

  1. 2.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.
  2. 3.One of the Cycloidei.

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