River Cocytus vs Cocytus

River Cocytus and Cocytus both are nouns.

Word	Noun	Adjective	Verb	Adverb
River Cocytus	Yes	No	No	No
Cocytus	Yes	No	No	No

As nouns, River Cocytus and Cocytus are synonyms defined as:

River Cocytus and Cocytus: (Greek mythology) a river in Hades that was said to be a tributary of the Acheron

River Cocytus (noun)	Cocytus (noun)
(Greek mythology) a river in Hades that was said to be a tributary of the Acheron	(Greek mythology) a river in Hades that was said to be a tributary of the Acheron