Phi (disambiguation)Topics referred to by the same term / From Wikipedia, the free encyclopedia Phi (Φ, φ, or ϕ) is the 21st letter of the Greek alphabet. Look up Phi or phi in Wiktionary, the free dictionary. Phi or PHI may also refer to:
Phi (Φ, φ, or ϕ) is the 21st letter of the Greek alphabet. Look up Phi or phi in Wiktionary, the free dictionary. Phi or PHI may also refer to: