Megas means great in size, degree, importance, or intensity. It occurs about 243 times in the NT and describes greatness of physical dimension, volume of sound ("a loud voice"), and the greatness of persons, events, or qualities that belong to the divine realm.
It gives English words like "mega-" (megaphone, megalith) and is the cognate of the Latin magnus. In the NT, it is frequently used to describe the greatness of God's acts, commandments, and eschatological realities.
The phrase megas ho Theos — "great is God" — echoes through Scripture. Titus 2:13 refers to "the blessed hope — the appearing of the glory of our great (megas) God and Savior, Jesus Christ." The greatness of Jesus is the greatness of God made visible.
The "great commandment" (megale entolē, Matthew 22:36–38) is not merely one among many — it is the organizing principle of all divine command: love God with all you are. The megas here is a category marker, not just an adjective.
Revelation is saturated with megas: the great tribulation, the great white throne, the great day of wrath, the great multitude. The eschatological drama is supremely great because the One who judges and saves is supremely great. The final word of history will be worship of the megas God.