cycloid

American  

[sahy-kloid] / ˈsaɪ klɔɪd /

adjective

1. resembling a circle; circular.

2. (of the scale of a fish) smooth-edged, more or less circular in form, and having concentric striations.

3. (of a fish) having such scales.

4. Psychiatry. of or noting a personality type characterized by wide fluctuation in mood within the normal range.

---

noun

1. a cycloid fish.

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

cycloid British  

/ ˈsaɪklɔɪd /

adjective

1. resembling a circle

2. (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

1. geometry the curve described by a point on the circumference of a circle as the circle rolls along a straight line Compare trochoid

2. a fish that has cycloid scales

cycloid Scientific  

/ sī′kloid′ /

1. Resembling a circle.

2. Thin, rounded, and smooth-edged, like a disk. Used of fish scales.

3. The curve traced by a point on the circumference of a circle that rolls on a straight line.

---

Other Word Forms

• cycloidal adjective
• cycloidally adverb

Etymology

Origin of cycloid

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

Example Sentences

Kahn played with natural light in the Fort Worth building, suffused with skylights, reflectors and cycloid barrel vaults.

From New York Times • May 4, 2022

When the distance from the center of the wheel to the ant is greater than the radius of the wheel, his path of motion is called a prolate cycloid.

From Textbooks • Mar. 30, 2016

First, let’s revisit the derivation of the parametric equations for a cycloid.

From Textbooks • Mar. 30, 2016

In this project we look at two different variations of the cycloid, called the curtate and prolate cycloids.

From Textbooks • Mar. 30, 2016

The cycloid is the simplest member of the class of curves known as roulettes.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 8 "Cube" to "Daguerre, Louis" by Various