river vs Nan

river and Nan both are nouns.

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

river (noun)	Nan (noun)
a large natural stream of water (larger than a creek)	a river of western Thailand flowing southward to join the Ping River to form the Chao Phraya