Potentate

po'-ten-tat (dunastes, "mighty one," from dunamai, "to be able"):

A person who possesses great power and authority. Only in 1 Timothy 6:15, "the blessed and only Potentate" (= God). The same Greek word is used of Zeus in Sophocles (Ant. 608), and of God in Apocrypha (e.g. Sirach 46:5; 2 Macc 15:3,13). It is used of men in Luke 1:52 (the King James Version "the mighty," the Revised Version (British and American) "princes") and Acts 8:27 ("of great authority").