roulette vs hypocycloid

roulette and hypocycloid both are nouns.

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

As nouns, hypocycloid is a hyponym of roulette; that is, hypocycloid 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
hypocycloid: a line generated by a point on a circle that rolls around inside another circle

Other hyponyms of roulette include cycloid, epicycloid.

roulette (noun)	hypocycloid (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 that rolls around inside 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