According to CanonSomeone who, together with other canons, is attached to a cathedral or collegiate church and whose main task is to ensure choral prayer. Law, a vicar is a substitute of a minister. In a dioceseAdministrative area headed by a bishop. In Belgium, there are eight dioceses: Bruges, Ghent, Antwerp, Mechelen-Brussels, Hasselt, Tournai, Liège and Namur., several vicars assist a bishopPriest in charge of a diocese. See also 'archbishop'.: priests who look after a certain policy area within the diocese (parishes, liturgy, etc.).