Related Clues:

• "Slow down!"
• 'Hold it, horse!'
• Reinforcement for a collar
• 'Hey, stop right there!'
• Horse's halter?
• Legal reprieve
• Steed stopper
• Jackson Browne tune
• "Hold on!"
• "Chill out!"
• "Take it easy!"
• Not leave home
• Cry of surprise
• Lab instruction?
• Reprieve