Answer: curtainraiser

AnswerCrossword Clue
CURTAINRAISERWarm-up act, e.g.
CURTAINRAISEROpening gun.
CURTAINRAISERAnimal act, usually
CURTAINRAISERPreliminary skit
CURTAINRAISERPlay before the play
CURTAINRAISERPre-play performance
CURTAINRAISERPreplay performance