Answer: PHI
The answer PHI has 174 possible clues. See the results below.
Possible Clues:
- It looks like an omicron with an iota through it
- Letter seen twice in Philadelphia
- Foreign character's expression of distaste for listeners
- Letter three before 15-Across
- Greek letter f
- Fourth-to-last Greek letter
- Greek symbol in the Golden Ratio
- Apt Greek letter for a Penn frat name
- Hard dividing an irrational number, which Diophantus once showed
- It’s three after 3-Down