engine driver vs operator

engine driver and operator both are nouns.

Word	Noun	Adjective	Verb	Adverb
engine driver	Yes	No	No	No
operator	Yes	No	No	No

As nouns, operator is a hypernym of engine driver; that is, operator is a word with a broader meaning than engine driver:

Other hypernyms of engine driver include manipulator.

engine driver (noun)	operator (noun)
the operator of a railway locomotive	an agent that operates some apparatus or machine
	someone who owns or operates a business
	a shrewd or unscrupulous person who knows how to circumvent difficulties
	a speculator who trades aggressively on stock or commodity markets
	(mathematics) a symbol or function representing a mathematical operation