highest, most exalted; as a title for God, "the Most High."
This word is the superlative of the ordinary word for "high," so at its simplest it means "highest." In the Bible almost every use turns that plain superlative into a name for God: "the Most High," the one lifted up above every other power. It is the standard Greek stand-in for the Hebrew title "Elyon" (עֶלְיוֹן), and the New Testament, especially Luke, reaches for it whenever it wants to underline God's supremacy.
The title carries a striking edge. It is spoken not only by angels and faithful voices but by those outside the covenant. A tormented man possessed by unclean spirits calls Jesus "Son of the Most High God," and a fortune-telling slave girl announces that Paul and his companions serve "the Most High God." Even hostile or pagan lips reach for this name, because "the Most High" was widely recognized across the ancient world as a way of naming the supreme God above all lesser powers.
A handful of uses keep the plain spatial sense. In the crowd's shout "Hosanna in the highest" and the angels' song "Glory to God in the highest," the word names not God but the loftiest place, the height of heaven from which praise rises and to which it returns.