a public civil officer invested with authority
The Hebrew shophetim, or judges, were magistrates having authority in the land (Deuteronomy 1:16-17). In Judges 18:7, the word “magistrate” (King James Version) is rendered in the Revised King James Version “possessing authority,” i.e., having power to do them harm by invasion.
In Acts 16:20, 22, 35-36, 38, the Greek term strategos, rendered “magistrate,” properly signifies the leader of an army, a general, one having military authority. The strategoi were the duumviri, the two praetors appointed to preside over the administration of justice in the colonies of the Romans. They were attended by the sergeants (properly lictors or “rod bearers”).