Noun
1. a social or business visitor;
"the room was a mess because he hadn't expected company"2. an investor who buys a call option
3. the bettor in a card game who matches the bet and calls for a show of hands
4. a person who announces the changes of steps during a dance;
"you need a fiddler and a caller for country dancing"5. someone who proclaims or summons in a loud voice;
"the callers were mothers summoning their children home for dinner"6. the person who convenes a meeting;
"who is the caller of this meeting?"7. the person initiating a telephone call;
"there were so many callers that he finally disconnected the telephone"