discoverer vs Hero of Alexandria

discoverer and Hero of Alexandria both are nouns.

Word	Noun	Adjective	Verb	Adverb
discoverer	Yes	No	No	No
Hero of Alexandria	Yes	No	No	No

discoverer (noun)	Hero of Alexandria (noun)
someone who is the first to observe something	Greek mathematician and inventor who devised a way to determine the area of a triangle and who described various mechanical devices (first century)
someone who is the first to think of or make something