epi·​cy·​cloid ˌe-pə-ˈsī-ˌklȯid How to pronounce epicycloid (audio)
: a curve traced by a point on a circle that rolls on the outside of a fixed circle
epicycloidal adjective

Illustration of epicycloid

Illustration of epicycloid
  • epicycloid E
  • traced by point P
  • on circle R
  • rolling on fixed circle F

Word History

First Known Use

circa 1696, in the meaning defined above

Time Traveler
The first known use of epicycloid was circa 1696

Dictionary Entries Near epicycloid

Cite this Entry

“Epicycloid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/epicycloid. Accessed 31 Jan. 2023.

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