nouns
(mathematics) a symbol or function representing a mathematical operation
domain category
a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement
is a type of (narrower)
(mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)
an agent that operates some apparatus or machine
"the operator of the switchboard"
someone who owns or operates a business
"who is the operator of this franchise?"
is a type of (narrower)
a person engaged in commercial or industrial business (especially an owner or executive)
a shrewd or unscrupulous person who knows how to circumvent difficulties
a speculator who trades aggressively on stock or commodity markets
is a type of (narrower)
someone who risks losses for the possibility of considerable gains