Related Clues:

• With frost, winter harbinger
• Kind of riser
• Before it gets crowded
• Before it's needed
• At the crack of dawn, say
• At cock's crow
• Unexpected, in a way
• Before sunrise
• Not just prompt
• "... and ___ to rise ..."
• Way before deadline
• When an eager date arrives
• Predawn
• Pioneering
• Before the crack of dawn