EPICYCLE

epicycle

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

Source: WordNet® 3.1


Etymology

Noun

epicycle (plural epicycles)

(astronomy) 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.

(mathematics) Any circle whose circumference rolls around that of another circle, thus creating a hypocycloid or epicycloid.

(organic chemistry) A ring of atoms joining parts of an already cyclic compound

Source: Wiktionary


Ep"i*cy`cle, n. Etym: [L. epicyclus, Gr. Cycle.]

1. (Ptolemaic Astron.)

Definition: 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. The schoolmen were like astronomers which did feign eccentries, and epicycles, and such engines of orbs. Bacon.

2. (Mech.)

Definition: A circle which rolls on the circumference of another circle, either externally or internally.

Source: Webster’s Unabridged Dictionary 1913 Edition



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Word of the Day

8 November 2024

REPLACEMENT

(noun) the act of furnishing an equivalent person or thing in the place of another; “replacing the star will not be easy”


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Coffee Trivia

Contrary to popular belief, coffee beans are not technically beans. They are referred to as such because of their resemblance to legumes. A coffee bean is a seed of the Coffea plant and the source for coffee. It is the pit inside the red or purple fruit, often referred to as a cherry. Just like ordinary cherries, the coffee fruit is also a so-called stone fruit.

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