Related Clues:

• Horse's halter
• Stop
• Rider's 'Stop!'
• 'Stop!'
• 'Holy smokes!'
• 'No way!'
• 'Awesome!'
• 'Hold it!'
• 'Wow!'
• Command to Dobbin
• 'Outta sight!'
• 'Not so fast!'
• 'Hold up!'
• Stop order?
• 'That's incredible!'