1.verb(of a king or other high-ranking aristocrat) To preside in a formal manner over an official assembly of courtiers and others in which entertainment is presented or affairs of state are considered.
2.verb(of a judge or equivalent official) To convene or preside over a trial or other legal proceeding in a court of law.
3.verb(by extension) To serve as the principal discussant or center of attention in an informal gathering of friends, associates, etc.