telegraphist vs operator

telegraphist and operator both are nouns.

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

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

Other hypernyms of telegraphist include manipulator.

telegraphist (noun)	operator (noun)
someone who transmits messages by telegraph	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