a subordinate government official: an appointed prefect or deputy who administered a province or city under a higher authority
This word names a rank of official rather than one named office. Wherever it appears it points to men who held delegated authority: they administered a district or a city, they answered to someone above them, and they nearly always acted as a group. It is a borrowed administrative title, not a native Hebrew word, which is why it carries the flavor of an imperial bureaucracy rather than of Israel's older tribal leadership.
In Ezra and Nehemiah the term describes the leading men of the restored community in Jerusalem, regularly paired with the free-born nobles (חֹר). In the oracles against Babylon and in Ezekiel's picture of Assyria and Babylon it describes the officers of foreign empires, paired with the higher provincial governor (פֶּחָה). The office is the same in both settings: a mid-level administrator who answered to a greater power, whether that power was the Persian crown, a Babylonian king, or the community's own governor.
Because the word is almost always plural, it points less to an individual and more to a class, the tier of officials through whom a government actually ran.