Ψ

noun

psi

The 23rd letter of the Greek alphabet (Ψ, ψ). Used as a symbol in physics, mathematics, psychology, and other sciences.

• Ψはギリシャ文も字じの23番ばん目めの文も字じです。

  Psi is the 23rd letter of the Greek alphabet.

• 量りょう子し力りき学がくでは、ψは波は動どう関かん数すうを表あらわす。

  In quantum mechanics, ψ represents the wave function.