opportunist vs operator

opportunist and operator both are nouns.

Word	Noun	Adjective	Verb	Adverb
opportunist	Yes	Yes	No	No
operator	Yes	No	No	No

As nouns, operator is a hyponym of opportunist; that is, operator is a word with a more specific, narrower meaning than opportunist:

opportunist: a person who places expediency above principle
operator: a shrewd or unscrupulous person who knows how to circumvent difficulties

Other hyponyms of opportunist include backscratcher, bottom feeder, carpetbagger, hustler, wheeler dealer, timeserver.

opportunist (noun)	operator (noun)
a person who places expediency above principle	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

opportunist (adjective)	operator (adjective)
taking immediate advantage, often unethically, of any circumstance of possible benefit