archaic letter of the Greek alphabet

Digamma or Wau (uppercase/lowercase Ϝ ϝ ς) was an old letter of the Greek alphabet. It was used before the alphabet converted its classical standard form. It looked like a Latin "F", but it was pronounced like "w". In the 5th century BC, people stopped using it because they could no longer pronounce the sound "w" in Greek. However, they kept it as a sign for the number "6" in the system of Greek numerals. It was originally called "Wau" because of its sound. Later, when the sound was lost, it was called "Digamma", which means "double Gamma", because it looks like a Gamma (Γ) with two hooks. The Latin letter F was also taken over from Wau.

Digamma uc lc.svg
Greek alphabet
Αα Alpha Νν Nu
Ββ Beta Ξξ Xi
Γγ Gamma Οο Omicron
Δδ Delta Ππ Pi
Εε Epsilon Ρρ Rho
Ζζ Zeta Σσ Sigma
Ηη Eta Ττ Tau
Θθ Theta Υυ Upsilon
Ιι Iota Φφ Phi
Κκ Kappa Χχ Chi
Λλ Lambda Ψψ Psi
Μμ Mu Ωω Omega
Other letters
Ϝϝ Digamma Ϟϟ Koppa
Ϛϛ Stigma Ϡϡ Sampi
Ͱͱ Heta Ϸϸ Sho
Ϻϻ San

In mathematics, the name "digamma" is used in digamma function, which is the derivative of the logarithm of gamma function (that is, ).[1][2][3]


  1. "Greek/Hebrew/Latin-based Symbols in Mathematics". Math Vault. 2020-03-20. Retrieved 2020-10-06.
  2. Weisstein, Eric W. "Digamma Function". mathworld.wolfram.com. Retrieved 2020-10-06.
  3. "Digamma Function | Brilliant Math & Science Wiki". brilliant.org. Retrieved 2020-10-06.

Other websites