Acheron vs river

Acheron and river both are nouns.

Word	Noun	Adjective	Verb	Adverb
Acheron	Yes	No	No	No
river	Yes	No	No	No

Acheron (noun)	river (noun)
(Greek mythology) a river in Hades across which the souls of the dead were carried by Charon	a large natural stream of water (larger than a creek)