'Epicycle' definitions:

Definition of 'epicycle'

From: WordNet
noun
A circle that rolls around (inside or outside) another circle; generates an epicycloid or hypocycloid

Definition of 'Epicycle'

From: GCIDE
  • Epicycle \Ep"i*cy`cle\, n. [L. epicyclus, Gr. ?; 'epi` upon + ? circle. See Cycle.]
  • 1. (Ptolemaic Astron.) A circle, whose center moves round in the circumference of a greater circle; or a small circle, whose center, being fixed in the deferent of a planet, is carried along with the deferent, and yet, by its own peculiar motion, carries the body of the planet fastened to it round its proper center. [1913 Webster]
  • The schoolmen were like astronomers which did feign eccentrics, and epicycles, and such engines of orbs. --Bacon. [1913 Webster]
  • 2. (Mech.) A circle which rolls on the circumference of another circle, either externally or internally. [1913 Webster] epicyclic