(of fish scales) rounded, thin, and smooth-edged, as those of the salmon
3. psychiatry
(of a type of personality) characterized by exaggerated swings of mood between elation and depression
See also cyclothymia
noun
4. geometry
the curve described by a point on the circumference of a circle as the circle rolls along a straight line
Compare trochoid (sense 1)
5.
a fish that has cycloid scales
Derived forms
cycloidal (cyˈcloidal)
adjective
cycloidally (cyˈcloidally)
adverb
cycloid in American English
(ˈsaɪˌklɔɪd)
noun
1. Geometry
a curve traced by any point on a radius, or an extension of the radius, of a circle which rolls without slipping through one complete revolution along a straight line in a single plane; trochoid
adjective
2.
circular
3.
designating or having fish scales that are roundish in form with smooth edges
4.
designating or of a cyclothymic person
Derived forms
cycloidal (cyˈcloidal) (saɪˈklɔɪdəl)
adjective
Word origin
Gr kykloeidēs, circular < kyklos (see wheel) + -eidēs, -oid