Definition of "Caller" :
noun: a social or business visitor
noun: the person initiating a telephone call
"There were so many callers that he finally disconnected the telephone."
noun: the person who convenes a meeting
"Who is the caller of this meeting?."
noun: someone who proclaims or summons in a loud voice
"The callers were mothers summoning their children home for dinner."
noun: a person who announces the changes of steps during a dance
"You need a fiddler and a caller for country dancing."
noun: the bettor in a card game who matches the bet and calls for a show of hands
noun: an investor who buys a call option
adjective: fresh
"Caller fish."
adjective: providing coolness
"Caller' is a Scottish term as in a caller breeze'."