| 1. | resembling a circle; circular. |
| 2. | (of the scale of a fish) smooth-edged, more or less circular in form, and having concentric striations. |
| 3. | (of a fish) having such scales. |
| 4. | Psychiatry. of or noting a personality type characterized by wide fluctuation in mood within the normal range. |
| 5. | a cycloid fish. |
| 6. | Geometry. a curve generated by a point on the circumference of a circle that rolls, without slipping, on a straight line. |
cycloid
the curve generated by a point on the circumference of a circle that rolls along a straight line. If r is the radius of the circle and theta (theta) is the angular displacement of the circle, then the polar equations of the curve are x = r(theta - sin theta) and y = r(1 - cos theta)
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