The term 'THEATER SIGNAL' can be broken down into two words, 'CUE' and 'THEATER'. A CUE is a signal given to actors on stage to indicate when they should begin or end their lines. It is usually given by the director or stage manager. In THEATER, cues are often given verbally, but they can also be given through hand signals, lights, or other visual indicators. The THEATER signal is an important part of the performance, as it helps keep the actors on track and ensures that the show runs smoothly.