2345: Digamma: Greek's Ghost Letter May 20, 2021
The letter G effectively replaced the letter Z in the Latin alphabet, but in the Greek alphabet the letter Ζ,ζ was also affected in its order in the alphabeta. The Hebrew and Phoenician letters, zayin, are both 7th and as numerals means (7) as is true in Greek numerals despite it being 6th in order. This is because the letter Ϛ,Ϝ known as Digamma which used to be 6th was used and eventually disfavored, merging with Sigma—namely the Lunate Sigma—creating the only Greek letter with 3 distinct forms (capital, lower case, and word-final). This had originally represented the sound /w/ which no longer exists in Greek.