Related Clues:

• P-like Greek letter
• Greek character
• Pi-sigma link
• Christogram component, perhaps
• Pi's follower
• Xi-pi go-between
• Pythagorean character
• Plato's O
• P, on a fraternity house
• Sigma neighbor
• Sigma follows it
• Christogram component, sometimes
• Aristotle's P
• Letter in Socrates' name
• "P" on fraternity row