disc vs discus

disc and discus both are nouns.

Word	Noun	Adjective	Verb	Adverb
disc	Yes	No	No	No
discus	Yes	No	No	No

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

disc (noun)	discus (noun)
a flat circular plate	a disk used in throwing competitions
sound recording consisting of a disk with a continuous groove; used to reproduce music by rotating while a phonograph needle tracks in the groove	an athletic competition in which a disk-shaped object is thrown as far as possible
(computer science) a memory device consisting of a flat disk covered with a magnetic coating on which information is stored
something with a round shape resembling a flat circular plate