Related Clues:

• Blast
• Sound of disapproval
• Least bit of concern
• Knee-slapper
• What 69-Across will grow up to do
• Rib-tickler
• Catcall
• Funny
• Laugh-a-minute
• Laugh riot
• Screech
• Vaudeville bit
• Standup bit
• Silence
• [That's awful!]