Related Clues:

• Droning lecture, e.g
• Drill — pest
• Induce ennui in
• Causing yawning
• Cause yarns
• Yawn cause
• Cause one to yawn
• Cause yawning
• Cause someone to yawn
• Displayed calibre
• Do tunneling
• A drill bit will do it
• Induce yawns from
• Gun barrel feature
• Cause to yawn, maybe