Related Clues:

• Headpiece?
• Honker
• Threshold
• Loudspeaker, informally
• Start with step or stop
• Entry
• Phone, slangily
• Gunpowder holder
• Road warning
• Little Boy Blue's instrument
• 'Let's Make a Deal' option
• 'In' place
• It can get you in on the ground floor
• Driver's alert
• Angry motorist's need