Concise Bible Dictionary:

In the Old Testament governor of a district (1 Kings 22:4747There was then no king in Edom: a deputy was king. (1 Kings 22:47); Esther 8:99Then were the king's scribes called at that time in the third month, that is, the month Sivan, on the three and twentieth day thereof; and it was written according to all that Mordecai commanded unto the Jews, and to the lieutenants, and the deputies and rulers of the provinces which are from India unto Ethiopia, an hundred twenty and seven provinces, unto every province according to the writing thereof, and unto every people after their language, and to the Jews according to their writing, and according to their language. (Esther 8:9); Esther 9:33And all the rulers of the provinces, and the lieutenants, and the deputies, and officers of the king, helped the Jews; because the fear of Mordecai fell upon them. (Esther 9:3)). In the New Testament proconsul, one who acted as governor of a Roman province with consular power (Acts 13:7-8,127Which was with the deputy of the country, Sergius Paulus, a prudent man; who called for Barnabas and Saul, and desired to hear the word of God. 8But Elymas the sorcerer (for so is his name by interpretation) withstood them, seeking to turn away the deputy from the faith. (Acts 13:7‑8)
12Then the deputy, when he saw what was done, believed, being astonished at the doctrine of the Lord. (Acts 13:12)
; Acts 18:1212And when Gallio was the deputy of Achaia, the Jews made insurrection with one accord against Paul, and brought him to the judgment seat, (Acts 18:12); Acts 19:3838Wherefore if Demetrius, and the craftsmen which are with him, have a matter against any man, the law is open, and there are deputies: let them implead one another. (Acts 19:38)).

Strong’s Dictionary of Greek Words:

from 473 and a superlative of 5228; instead of the highest officer, i.e. (specially) a Roman proconsul
KJV Usage: