cue
/ˈkyü/
noun
the letter q
noun
a signal (such as a word, phrase, or bit of stage business) to a performer to begin a specific speech or action
something serving a comparable purpose : hint
a feature indicating the nature of something perceived
That last line is your cue to exit the stage.
I'll take that yawn as my cue to leave.
verb
to give a cue to : prompt
to insert into a continuous performance
cued the band to begin