/kawl"boy'/ , n.
1. a boy or man who summons actors, as from their dressing rooms, shortly before they are due to go on stage.
2. a bellhop.
3. Also, call boy . a male prostitute who arranges appointments with clients by telephone.
4. Also, call-boy, call boy . Railroads Slang. a railroad employee responsible for ensuring that members of a train crew are on hand for their regular runs and for notifying them of an extra run.
[ 1835-45; CALL + BOY ]