Bo Hai vs Bohai Sea

Bo Hai and Bohai Sea both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bo Hai	Yes	No	No	No
Bohai Sea	Yes	No	No	No

As nouns, Bo Hai and Bohai Sea are synonyms defined as:

Bo Hai and Bohai Sea: an inlet of the Yellow Sea, on the coast of Eastern China

Other synonyms of Bo Hai include Po Hai.

Bo Hai (noun)	Bohai Sea (noun)
an inlet of the Yellow Sea, on the coast of Eastern China	an inlet of the Yellow Sea, on the coast of Eastern China