USHER (O. Fr. ussier, uissier, mod. huissier, from Lat. ostiarius, a door-keeper, ostium, doorway, entrance, os, mouth), properly an official or servant who guards the entrance to a building, admits those who have the right of admission and keeps out strangers; such functions as the introduction of those who are admitted, the conducting them to their seats or to the presence of the persons receiving them and the keeping of order and silence are also performed by them. The "ushers" of a law-court are familiar officials of this kind. The name is also applied to various members of the British royal household, in which there are several "gentlemen-ushers." The four principal British orders of knighthood style one of their chief officers "usher"; thus there is a gentleman-usher of the Black Rod, who is also one of the high officials of the House of Lords (see further, Black Rod, and Knighthood and Chivalry,—Orders of Knighthood). A common usage of the word, now obsolescent, is for an undermaster at a school.