From SuspireWiki

(n., formal)

The lord of any domain who receives his authority, territory and/or title directly from the Prince (q.v.), even if he is not strictly the Prince’s vassal. In cities with especially strict feudal codes, the Prince may only appoint Regents directly below his own station in the feudal hierarchy; he may not appoint Regents as vassals of other lords. In practice, the overlords directly subordinate to the Prince, whether appointed by him, a predecessor or some other body (such as the Primogen) is also called a Regent. “You may be my landlord, Haunt, but I am a Regent now, and you will be careful how you speak to me.”