Digamma
the name given to a letter in the oldest Greek alphabet, which early fell into disuse, being retained longest in the Æolian dialect. It is considered to have had the power of the English w or v, and is frequently represented in Latin by u (v): thus, Gr. oikos Lat. vicus, Eng. wick; Gr. oinos Lat. vinum, Eng. wine. See ALPHABET.