Ψ

Symbol

 * 1) Sometimes used as a typographic substitute for $⟨♆⟩$ (Neptune).
 * 2)  Mercury.

Etymology
grc. The Phoenician alphabet has no letter that is similar in either shape or sound. The Linear B alphabet has three similar-looking letters,, , and , but none of them represents a sound similar to either the Eastern Greek pronunciation or the Western Greek pronunciation.

Letter

 * 1) The letter psi, the 23rd letter of the ancient Greek alphabet.

Letter

 * 1) The upper case letter psi (ψι), the 23rd letter of the modern Greek alphabet.