Don vs Don River

Don and Don River both are nouns.

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

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

Don and Don River: a European river in southwestern Russia; flows into the Sea of Azov

Don (noun)	Don River (noun)
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
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