operator

(noun) (mathematics) a symbol or function representing a mathematical operation.

(noun) an agent that operates some apparatus or machine. Synonyms: manipulator. Example: "The operator of the switchboard."

(noun) someone who owns or operates a business. Example: "Who is the operator of this franchise?."

(noun) a shrewd or unscrupulous person who knows how to circumvent difficulties. Synonyms: hustler, wheeler dealer.

(noun) a speculator who trades aggressively on stock or commodity markets.