The crossword solution for the term 'SIGNAL TO ENTER' is 'CUE'. A CUE is a signal that is given to indicate that it is time to begin or enter something. It is commonly used in theatre, film, and television production to indicate when an actor should enter or begin their performance. Cues can also be used in sports, such as when a referee signals the start of a game. In general, a CUE is a signal that is used to indicate the start of something.