(1):

(n.) Originally, a person put in charge of something especially, a chief officer, magistrate, or keeper, as of a county, town, hundred, or castle; one to whom power/ of custody or care are intrusted.

(2):

(n.) A sheriff's deputy, appointed to make arrests, collect fines, summon juries, etc.

(3):

(n.) An overseer or under steward of an estate, who directs husbandry operations, collects rents, etc.