Related Clues:

• Private eye, for short
• See 32-Across
• ...
• Geometric ratio
• Circumference divided by diameter
• Circle ratio
• Det.
• 16th Greek letter
• Common ratio
• 3.1416
• 3.14
• Hole or shaft in the ground.
• Det
• 'Life of --'
• The ratio of a circle's circumference to its diameter