epicycloid

[ ep-uh-sahy-kloid ]
/ ˌɛp əˈsaɪ klɔɪd /

noun Geometry.

a curve generated by the motion of a point on the circumference of a circle that rolls externally, without slipping, on a fixed circle. Equation: x = (a + b) cos(θ) − b cos[(a + b)θ/b] and y = (a + b) sin(θ) − b sin[(a + b)θ/b].
Compare epitrochoid.

Origin of epicycloid

First recorded in 1780–90; epicycle + -oid

OTHER WORDS FROM epicycloid

ep·i·cy·cloi·dal, adjective

Words nearby epicycloid

epicureanism, epicurus, epicuticle, epicycle, epicyclic train, epicycloid, epicycloidal gear, epicycloidal wheel, epicystitis, epicystotomy, epidaurus

Example sentences from the Web for epicycloid

British Dictionary definitions for epicycloid

epicycloid
/ (ˌɛpɪˈsaɪklɔɪd) /

noun

the curve described by a point on the circumference of a circle as this circle rolls around the outside of another fixed circle, the two circles being coplanar Compare hypocycloid, cycloid (def. 4)

Derived forms of epicycloid

epicycloidal, adjective

Scientific definitions for epicycloid

epicycloid
[ ĕp′ĭ-sī′kloid′ ]

The curve described by a point on the circumference of a circle as the circle rolls on the outside of the circumference of a second, fixed circle.