Port Arthur vs Lushun

Port Arthur and Lushun both are nouns.

Word	Noun	Adjective	Verb	Adverb
Port Arthur	Yes	No	No	No
Lushun	Yes	No	No	No

As nouns, Port Arthur and Lushun are synonyms defined as:

Port Arthur and Lushun: a major port city in northeastern China on the Liaodong Peninsula; now a part of Luda

Other synonyms of Port Arthur include Lushunkou District.

Port Arthur (noun)	Lushun (noun)
a battle in the Chino-Japanese War (1894); Japanese captured the port and fortifications from the Chinese	a major port city in northeastern China on the Liaodong Peninsula; now a part of Luda
a major port city in northeastern China on the Liaodong Peninsula; now a part of Luda