cycloid.

/sahy-kloid/US // ˈsaɪ klɔɪd //UK // (ˈsaɪklɔɪd) //

摆线,摆线型,摆线针轮,摆线虫

Definitions

1.
- ›resembling a circle; circular.
- › smooth-edged, more or less circular in form, and having concentric striations.
- › having such scales.
- ›Psychiatry. of or noting a personality type characterized by wide fluctuation in mood within the normal range.

1.
- ›a cycloid fish.
- ›Geometry. a curve generated by a point on the circumference of a circle that rolls, without slipping, on a straight line.

In brief—distinct grounds, and vivid circular or cycloid figures, of no meaning, are here Median laws.
In 1644 he published a tract on the properties of the cycloid in which he suggested a solution of the problem of its quadrature.
Other sharks had piercing teeth (Cladoselache and Cladodus); some, the petalodonts, had peculiar cycloid cutting teeth.
The tail is diphycercal in all, ending in a long point, and the body is covered with cycloid scales.
The Holoptychiidæ have the pectoral fins acute, the scales cycloid, enameled, and the teeth very complex.