noun

1. a bit of dialogue, action, or music that is a signal for an actor's entrance or speech, or for the working of curtains, lights, sound effects, etc.
2. Music a gesture or written device used to signal the entry of one or more instrumentalists or vocalists
3. anything serving as a signal to do something
4. an indirect suggestion; hint
5. Now Rare
   1. the role that one is assigned to play
   2. a necessary course of action
6. Archaic frame of mind; mood; temperament
7. Psychol. a secondary stimulus that guides behavior, often without entering consciousness

Etymology: < q, Q, used in plays in 16th & 17th c. to indicate actors' entrances; prob. abbrev. of some L word (as quando, when, qualis, in what manner)

transitive verb cued, cuing cu′·ing or cueing cue′·ing