Related Clues:

• Joke
• Quip
• Equivoque
• Insignificant
• 'Miró, Miró, on the wall,' e.g.
• Wit's end?
• 'Let us spray,' e.g.
• Play on words
• ''Mir—, Mir—, on the wall,'' e.g.
• Bit of wit
• Bit of Cerf humor
• 20-, 39- or 53-Across, say
• Many an 'Airplane!' gag
• Bad humor?
• Cause for a groan