Nouns

(n)operator(mathematics) a symbol or function representing a mathematical operation
(n)operator, manipulatoran agent that operates some apparatus or machine“the operator of the switchboard”
(n)operatorsomeone who owns or operates a business“who is the operator of this franchise?”
(n)hustler, wheeler dealer, operatora shrewd or unscrupulous person who knows how to circumvent difficulties
(n)operatora speculator who trades aggressively on stock or commodity markets