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Related to cycloidal: Cycloidal propeller
top: surface view of cycloid scales of a bony fish
bottom: The parametric equations of this cycloid are
x = r(θ - sin θ),
y = r(1 - cos θ).cycloid
1. Resembling a circle.
a. Relating to or being a kind of fish scale that is thin, rounded, and smooth-edged and often shows concentric growth rings.
b. Having cycloid scales.
3. Psychology Afflicted with or relating to cyclothymia.
The curve traced by a point on the circumference of a circle that rolls on a straight line.
[French cycloïde, from Greek kukloeidēs, circular : kuklos, circle; see kwel- in Indo-European roots + -oeidēs, -oid.]
cy·cloi′dal (-kloid′l) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.