What is Cue ?
Cue is (noun) 1. (in a play) words after which you have to speak or act He missed his cue and had to be prompted. The gunshot is your cue to rush onto the stage screaming. to take your cue from someone to do as someone else does Watch the managing director during the negotiations and take your cue from him. 2. a long stick for playing billiards or snooker Before playing his shot, he put some chalk on the tip of his cue.
source: Easier English, Student Dictionary Upper Intermediate Level