Digamma

Archaic letter of the Greek alphabet

Digamma or wau is an archaic letter of the Greek alphabet. It originally stood for the sound but it has remained in use principally as a Greek numeral for 6. Whereas it was originally called waw or wau, its most common appellation in classical Greek is digamma; as a numeral, it was called episēmon during the Byzantine era and is now known as stigma after the Byzantine ligature combining σ-τ as ϛ.

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