Marine vs devil dog

Marine and devil dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
Marine	Yes	No	No	No
devil dog	Yes	No	No	No

As nouns, Marine and devil dog are synonyms defined as:

Other synonyms of Marine include leatherneck, shipboard soldier.

Marine (noun)	devil dog (noun)
a member of the United States Marine Corps	a member of the United States Marine Corps