Related Clues:

• Open mouth wide
• Something boring to do when sleepy?
• Upcoming part for John Wayne in drag
• Any sort of casing with an opening
• Show no interest as new fashion turns up
• Road back north is a bore
• Deviation provided by Nationalist in boring event
• Hint to a unexciting speaker
• Response to a drone
• Involuntary sign of tiredness or boredom
• [Bo-o-ring!]
• Opening at an early-morning class?
• Be open wide
• 'B-o-r-r-r-ing!'
• Demonstrate disinterest