superior rectus vs eye muscle

superior rectus and eye muscle both are nouns.

Word	Noun	Adjective	Verb	Adverb
superior rectus	Yes	No	No	No
eye muscle	Yes	No	No	No

As nouns, eye muscle is a hypernym of superior rectus; that is, eye muscle is a word with a broader meaning than superior rectus:

superior rectus: the ocular muscle whose contraction turns the eyeball upward and medially
eye muscle: one of the small muscles of the eye that serve to rotate the eyeball

Other hypernyms of superior rectus include ocular muscle.

superior rectus (noun)	eye muscle (noun)
the ocular muscle whose contraction turns the eyeball upward and medially	one of the small muscles of the eye that serve to rotate the eyeball