Satrap translates the Hebrew achashdarpan, which is itself a transliteration of an originally Persian word meaning the governor of a province (satrapy) under the Persian administration. The Persian empire was divided into twenty satrapies (which were in turn divided into smaller units). Syrio-Palestine came under the satrapy of 'Trans-Euphrates' (Ezra 8:36; Neh 3:7).
When Alexander the Great conquered the Persian Empire, he kept the administrative structure in place, and from that practice, the word entered into Greek and, then, English.
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