river vs Don

river and Don both are nouns.

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

river (noun)	Don (noun)
a large natural stream of water (larger than a creek)	a Spanish courtesy title or form of address for men that is prefixed to the forename
	a European river in southwestern Russia; flows into the Sea of Azov
	Celtic goddess; mother of Gwydion and Arianrhod; corresponds to Irish Danu
	a Spanish gentleman or nobleman