roulette vs epicycloid

roulette and epicycloid both are nouns.

Word	Noun	Adjective	Verb	Adverb
roulette	Yes	No	No	No
epicycloid	Yes	No	No	No

As nouns, epicycloid is a hyponym of roulette; that is, epicycloid is a word with a more specific, narrower meaning than roulette:

roulette: a line generated by a point on one figure rolling around a second figure
epicycloid: a line generated by a point on a circle rolling around another circle

Other hyponyms of roulette include cycloid, hypocycloid.

roulette (noun)	epicycloid (noun)
a gambling game in which players bet on which compartment of a revolving wheel a small ball will come to rest in	a line generated by a point on a circle rolling around another circle
a wheel with teeth for making a row of perforations
a line generated by a point on one figure rolling around a second figure