A person who shows people to their seats, especially in a theater or at a wedding. The usher guided us to our seats in the crowded theater.
An official in a court of law who swears in jurors and witnesses and maintains order. The usher called the court to order before the judge entered the room.
A person who escorts people to their seats in a church, especially during a wedding or funeral. The usher handed out programs as guests arrived for the wedding ceremony.