Related Clues:

• Like sentries
• Like an excellent guard dog
• On top of things
• Engage in fisticuffs
• Not drowsy
• Word with red or on
• Observant
• Red state?
• Cereal buy
• UPS Store buy
• Like a worthy watchdog
• Exchange blows
• Having heightened senses
• Go rounds in a ring
• APB, for one