epitrochoid

[ ep-i-troh-koid ]

Geometry.

1. a plane curve generated by the motion of a fixed point on the radius or extension of the radius of a circle that rolls externally, without slipping, on a fixed circle. The epitrochoid is a generalization of the epicycloid.

Word History and Origins

Origin of epitrochoid¹

First recorded in 1835–45; epi- + trochoid

Example Sentences

The curve may be regarded as an epitrochoid (see Epicycloid) in which the rolling and fixed circles have equal radii.

From Project Gutenberg