rocket scientist vs engineer

rocket scientist and engineer both are nouns.

Word	Noun	Adjective	Verb	Adverb
rocket scientist	Yes	No	No	No
engineer	Yes	No	Yes	No

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

rocket scientist: an engineer who builds and tests rockets
engineer: a person who uses scientific knowledge to solve practical problems

Other hypernyms of rocket scientist include applied scientist, technologist.

rocket scientist (noun)	engineer (noun)
an engineer who builds and tests rockets	a person who uses scientific knowledge to solve practical problems
a clever thinker	the operator of a railway locomotive

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