Help support Wordnik by adopting your favorite word!

Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. In Ptolemaic cosmology, a small circle, the center of which moves on the circumference of a larger circle at whose center is the earth and the circumference of which describes the orbit of one of the planets around the earth.
  • n. Mathematics A circle whose circumference rolls along the circumference of a fixed circle, thereby generating an epicycloid or a hypocycloid.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A small circle whose centre is on the circumference of a larger circle; in Ptolemaic astronomy it was seen as the basis of revolution of the "seven planets", given a fixed central Earth.
  • n. Any circle whose circumference rolls around that of another circle, thus creating a hypocycloid or epicycloid.

from the GNU version of the Collaborative International Dictionary of English

  • n. 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.
  • n. A circle which rolls on the circumference of another circle, either externally or internally.

from The Century Dictionary and Cyclopedia

  • n. A circle moving upon or around another circle, as one of a number of wheels revolving round a common axis. See epicyclic train, under epicyclic.
  • n. In the Ptolemaic system of astronomy, a little circle, conceived for the explanation of planetary motion, whose center was supposed to move round in the circumference of a greater circle; a small circle whose center, being fixed in the deferent of a planet, was supposed to be carried along with the deferent, and yet by its own peculiar motion to carry the body of the planet fastened to it round its proper center. Copernicus also made use of epicycles, which, however, were banished by Kepler.
  • n. In mod. astron., sometimes used for the geocentric path of a planet, or its path relative to the earth regarded as fixed.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a circle that rolls around (inside or outside) another circle; generates an epicycloid or hypocycloid

Etymologies

Middle English epicicle, from Late Latin epicyclus, from Greek epikuklos : epi-, epi- + kuklos, circle.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin epicyclus, from Ancient Greek ἐπίκυκλος, from ἐπί ("upon") + κύκλος ("circle"). (Wiktionary)

Examples

  • For the epicycle is a sphere which changes place in the circumference of the large sphere.

    A History of Mediaeval Jewish Philosophy

  • Zizka makes an interesting point, I think, with his "epicycle" comment, but I don't believe that the rules that cover exceptions are necessarily made up.

    languagehat.com: LINGUISTIC MUTATION.

  • I was thinking primarily of the "epicycle" business in Greek astronomy, where when the observations didn't match the theory, the theory wasn't reconsidered, additional elements were just bolted on for support.

    ScienceBlogs Channel : Life Science

  • Consequently, the current spate of privatization is correctly viewed as a sort of minor epicycle in a massive trend that has been moving rather steadily in the opposite direction.

    David Isenberg: Admiral Bob's Global Security: The Future of PSC?

  • How was the machinery and holes arranged for the epicycle?

    Bukiet on Brooklyn Books

  • Boulliau: “The axiom that the celestial motions are circular or composed of circles must stand, and therefore I reject and repudiate his ellipses unless he should suppose them to be described by means of a Copernican or Tychonic epicycle.” (letter to Gassendi 1633)

    Bukiet on Brooklyn Books

  • However, if American decline were to turn out to be true in this current epicycle of the world, it would be not so much on account of movements outside the United States as inside.

    The Volokh Conspiracy » They Made a Multilateralism and Called It Peace

  • The question posed near the end of the article, then, is whether neoclassical economists are just adding new wrinkles when they ought to be switching paradigms altogether — adding epicycle after epicycle to a Ptolemaic model in a vain attempt to fend of Copernicus.

    Can We Call Them “Neoclassical Deniers”?

  • By development, I presume you mean the arbitrary, ad-hoc, epicycle-upon-epicycle approach that attempts to salvage the central dogmatic principles?

    Approaching Difference, Not Likeness

  • "By development, I presume you mean the arbitrary, ad-hoc, epicycle-upon-epicycle approach that attempts to salvage the central dogmatic principles?"

    Approaching Difference, Not Likeness

Comments

Log in or sign up to get involved in the conversation. It's quick and easy.