Irrawaddy vs river

Irrawaddy and river both are nouns.

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

Irrawaddy (noun)	river (noun)
the main river of Myanmar rising in the north and flowing south through the length of Burma to empty into the Andaman Sea	a large natural stream of water (larger than a creek)