digamma
/daɪˈgæmə/noun
- the sixth letter of the early Greek alphabet (Ϝ, ϝ), probably pronounced as 'w'. It became obsolete before the Classical period.早期希腊语的第六个字母（发音大概如"w", 在古典时期到来之前就不再使用）。
词源
late 17th cent.: via Latin from Greek, from di- 'twice' + GAMMA （because of the shape of the letter, resembling gamma （Γ） with an extra stroke）.