United States Marine Corps vs United States Marines

United States Marine Corps and United States Marines both are nouns.

Word	Noun	Adjective	Verb	Adverb
United States Marine Corps	Yes	No	No	No
United States Marines	Yes	No	No	No

As nouns, United States Marine Corps and United States Marines are synonyms defined as:

United States Marine Corps and United States Marines: an amphibious division of the United States Navy

Other synonyms of United States Marine Corps include Marine Corps, Marines, US Marine Corps, USMC.

United States Marine Corps (noun)	United States Marines (noun)
an amphibious division of the United States Navy	an amphibious division of the United States Navy