Po vs Po River

Po and Po River both are nouns.

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

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

Po (noun)	Po River (noun)
a European river; flows into the Adriatic Sea	a European river; flows into the Adriatic Sea
a radioactive metallic element that is similar to tellurium and bismuth; occurs in uranium ores but can be produced by bombarding bismuth with neutrons in a nuclear reactor