Related Clues:

• Surprise one's costar
• Do improv
• Speak off-the-cuff
• Off-the-cuff quip
• Drift from the script
• Improv line
• Script departure
• Fashion lines?
• Forgo a prepared speech
• Unmemorized remark
• Unscripted comment
• Surprise one's co-star
• Ignore the script
• Eschew the TelePrompTer
• Improvise lines