marine engineer vs engineer

marine engineer and engineer both are nouns.

Word	Noun	Adjective	Verb	Adverb
marine engineer	Yes	No	No	No
engineer	Yes	No	Yes	No

As nouns, engineer is a hypernym of marine engineer; that is, engineer is a word with a broader meaning than marine engineer:

marine engineer: a naval officer responsible for the operation and maintenance of the ship's engines
engineer: a person who uses scientific knowledge to solve practical problems

Other hypernyms of marine engineer include applied scientist, technologist.

marine engineer (noun)	engineer (noun)
a naval officer responsible for the operation and maintenance of the ship's engines	a person who uses scientific knowledge to solve practical problems
	the operator of a railway locomotive

marine engineer (verb)	engineer (verb)
	plan and direct (a complex undertaking)
	design as an engineer