Related Clues:

• Ancient
• Primitive
• Before the due date
• Premature
• See 51-Across
• In good time
• Jumping the gun
• Before curfew
• Like an eager guest, maybe
• ''... and --- to rise ...''
• More than punctual
• Before the bell
• Like some birds?
• Like the bird that catches the worm
• Before dawn, perhaps