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.
Origin of cycloid
Related formscy·cloi·dal, adjectivecy·cloi·dal·ly, adverb
First recorded in 1655–65, cycloid
is from the Greek
like a circle. See cycl-
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for cycloid
Historical Examples of cycloid
It is not yet known to what philosopher we owe the invention of the cycloid.
Pascal is said to have written his treatise on the cycloid from a religious motive.
So that it is a kind of Cycloid, of which, however, the points can be found geometrically.
Rather it travels along a cycloid, bending back upon itself, following the movement of man.
In brief—distinct grounds, and vivid circular or cycloid figures, of no meaning, are here Median laws.
British Dictionary definitions for cycloid
resembling a circle
(of fish scales) rounded, thin, and smooth-edged, as those of the salmon
psychiatry (of a type of personality) characterized by exaggerated swings of mood between elation and depressionSee also cyclothymia
Derived Formscycloidal, adjectivecycloidally, adverb geometry the curve described by a point on the circumference of a circle as the circle rolls along a straight lineCompare trochoid (def. 1)
a fish that has cycloid scales
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.