ep·i·cy·cle

(ĕp′ĭ-sī′kəl)

1. 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.

2. Mathematics A circle whose circumference rolls along the circumference of a fixed circle, thereby generating an epicycloid or a hypocycloid.

[Middle English epicicle, from Late Latin epicyclus, from Greek epikuklos : epi-, epi- + kuklos, circle; see k^wel- in Indo-European roots.]

ep′i·cyc′lic (-sĭk′lĭk, -sī′klĭk) adj.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

epicycle

(ˈɛpɪˌsaɪkəl)

1. (Astronomy) astronomy (in the Ptolemaic system) a small circle, around which a planet was thought to revolve, whose centre describes a larger circle (the deferent) centred on the earth

2. (Mathematics) a circle that rolls around the inside or outside of another circle, so generating an epicycloid or hypocycloid

[C14: from Late Latin epicyclus, from Greek epikuklos; see epi-, cycle]

epicyclic, ˌepiˈcyclical adj

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

ep•i•cy•cle

(ˈɛp əˌsaɪ kəl)

n.

1. a circle whose center moves around in the circumference of a larger circle: used in Ptolemaic astronomy to account for irregularities in planetary motion.

2. a circle that rolls, externally or internally, without slipping, on another circle, generating an epicycloid or hypocycloid.

[1350–1400; Middle English < Middle French < Late Latin epicyclus < Greek epíkyklos. See epi-, cycle]

ep`i•cy′clic (-ˈsaɪ klɪk, -ˈsɪk lɪk) adj.

ThesaurusAntonymsRelated WordsSynonymsLegend:

Noun

epicycle - a circle that rolls around (inside or outside) another circle; generates an epicycloid or hypocycloid

circle - ellipse in which the two axes are of equal length; a plane curve generated by one point moving at a constant distance from a fixed point; "he calculated the circumference of the circle"

Translations

epiciclo

epicycle

n → Epizykel m

Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007

Mentioned in

References in classic literature

It was gravely said by some of the prelates in the Council of Trent, where the doctrine of the Schoolmen bare great sway, that the Schoolmen were like astronomers, which did feign eccentrics and epicycles, and such engines of orbs, to save the phenomena; though they knew there were no such things; and in like manner, that the Schoolmen had framed a number of subtle and intricate axioms, and theorems, to save the practice of the church.

View in context

But when it came to almagest and astrolabe, the counting of figures and reckoning of epicycles, away would go her thoughts to horse and hound, and a vacant eye and listless face would warn the teacher that he had lost his hold upon his scholar.

View in context

But Wootton is more appreciative in a chapter titled "Profit: The Invisible Hand," in which he argues that for Smith "the most important effect of commerce and manufactures is...not wealth or population increase but liberty and security; and liberty and security make possible a happy life, rather than a life blighted by fear and violence, and a virtuous life, rather than a life spent scrambling for subsistence and survival." In this way, "invisible hand processes are not just some peculiar epicycle within Smith's elaborate system; they are the providential mechanism which reconciles wealth and virtue."

Intellectual Revolution for Fun and Profit

when they come to model heaven And calculate the stars, how they will wield The mighty frame, how build, unbuild, contrive To save appearances, how gird the sphere With centric and eccentric scribbled o'er, Cycle and epicycle, orb in orb (8.79-84) These "quaint opinions wide" (8.78) are the product of writing, scribbling over and confusing human understanding of the natural world.

Unspeakable Creation: Writing in Paradise Lost and Early Modern Mathematics

The most fully developed example of the presumptive argument is found in Pingree's hypothesis of a Greek origin for the model of the double epicycle in Indian astronomical mathematics (pp.

Pathways into the Study of Ancient Sciences: Selected Essays

The city commissioned 400 new projects, including this weekend's Epicycle event (think Cirque du Soleil-style acrobatics within a metal circle of immense scale).

Hull proves a worthy winner in Culture stakes

The aim of the work is to obtain analytical and graphical dependences of the efficiency between the driving and the driven links in single-stage single-row and two-row differential gears with closed hydraulic system, when the driving link is the carrier, and the driven one is the epicycle, and vice versa.

THE EFFICIENCY OF THE DIFFERENTIAL GEAR TO DEVICES FOR CONTROLLING THE SPEED CHANGE THROUGH A SUN GEAR

Epicycloids--curves generated by a point on the circumference of a circle (the epicycle)--or hypocycloids (Figure 1)--curves that roll on the inside of the circle--are examples of adding prefixes and suffixes.

Creating words in mathematics

(In Ptolemaic terms, this function is fulfilled by the epicycle, appropriately enough a circle that is going around a circle that is going around....)

Loose Leaves, Lost Leaves, and the Text of Piers Plowman

Hereafter, when they come to model heav'n And calculate the stars, how they will wield The mighty frame, how build, unbuild, contrive To save appearances, how gird the sphere With centric and eccentric scribbled o'er, Cycle in epicycle, orb in orb.

Encounter between literature and science: Galileo's impact on Milton