Related Clues:

• Seventeenth Greek letter
• Euripides character?
• P-shaped Greek letter
• Fraternity chapter #17
• P, on some sweaters
• Peloponnesian P
• P on a frat house
• Physicist's symbol for density
• A Greek letter
• P, to Pythagoras
• It's between pi and sigma
• Fraternity 'P'
• Air-density symbol
• Pythagoras's P
• 55-Down letter