cycloid

[ sahy-kloid ]

Phonetic (Standard)IPA

adjective

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

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

cycloid

/ ˈsaɪklɔɪd /

resembling a circle
(of fish scales) rounded, thin, and smooth-edged, as those of the salmon
See cyclothymia
psychiatry (of a type of personality) characterized by exaggerated swings of mood between elation and depression See also cyclothymia

See trochoid
geometry the curve described by a point on the circumference of a circle as the circle rolls along a straight line Compare trochoid
a fish that has cycloid scales

cycloid

/ sī′kloid′ /

Resembling a circle.
Thin, rounded, and smooth-edged, like a disk. Used of fish scales.
The curve traced by a point on the circumference of a circle that rolls on a straight line.

Origin of cycloid¹

First recorded in 1655–65, cycloid is from the Greek word kykloeidḗs like a circle. See cycl-, -oid

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.

April 18, 2024petrichor

[pet-ri-kawr]

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