[Olog-hai]

Digamma is apparently cognate to the Hebrew, Aramaic and Phoenician letter waw or vav, which also had the numerical value of 6. (The literal meaning of “waw” is “hook”.)

[Verginius Rufus]

Definitely. The Greek alphabet is derived from the Phoenician alphabet and largely keeps the same order of letters. The Greek names of the letters are slightly garbled versions of the Phoenician/Canaanite/Hebrew names...aleph into alpha, beth into beta, etc.

[Verginius Rufus]

The digamma (pronounced like a W) was lost in most Greek versions of the alphabet (each city-state had its own version until the Ionic alphabet became standard) because the "w" became silent. A number of Greek words originally had a W which was lost (like the W in sword in English). Sometimes Homeric lines seem unmetrical until it is realized that in Homer's time there was a W sound still being pronounced.

One example is Greek oinos "wine" (cf. Latin vinum which had a W sound for the V)--it was woinos earlier in Greek. Or Greek ergon, originally wergon, which is cognate with English "work" (G in Greek often corresponds to K in English).