Milk vs Milk River

Milk and Milk River both are nouns.

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

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

Milk and Milk River: a river that rises in the Rockies in northwestern Montana and flows eastward to become a tributary of the Missouri River

Milk (noun)	Milk River (noun)
a river that rises in the Rockies in northwestern Montana and flows eastward to become a tributary of the Missouri River	a river that rises in the Rockies in northwestern Montana and flows eastward to become a tributary of the Missouri River