The modern Greek alphabet is missing some of the letters used in ancient times. What are these missing letters, and what happened to them?

Greek, the oldest written language still in use, has shaped culture, philosophy, and science for over 3,700 years.

The Greek alphabet, traditionally believed to have emerged in the eighth century BC, is now undergoing reevaluation thanks to groundbreaking research at Leiden University. The writing system is ...

In Monday's puzzle, 27-Across read [Greek letter X], which was either a gimme or a "Now, which one is that again..?" for most solvers. CHI it was, but it is tough to keep track sometimes. Four of the ...