Related Clues:

• Telegram "period"
• Tops a different way?
• Octagonal traffic sign
• It's followed by "Who goes there?"
• Call a halt to
• "Freeze!"
• Pause
• 'Uncle!'
• Octagon inscription
• Octagonal sign
• Cry from a tickled person
• Guard's shout
• Word on the street
• Telegram punctuation
• Marching order