supercargo vs ship's officer

supercargo and ship's officer both are nouns.

Word	Noun	Adjective	Verb	Adverb
supercargo	Yes	No	No	No
ship's officer	Yes	No	No	No

As nouns, ship's officer is a hypernym of supercargo; that is, ship's officer is a word with a broader meaning than supercargo:

supercargo: an officer on a merchant ship in charge of the cargo and its sale and purchase
ship's officer: a person authorized to serve in a position of authority on a vessel

Other hypernyms of supercargo include officer.

supercargo (noun)	ship's officer (noun)
an officer on a merchant ship in charge of the cargo and its sale and purchase	a person authorized to serve in a position of authority on a vessel