cassock

[cassock]
Italian: casacca, great-coat

A gown or soutane, usually black, the ordinary outer garb of clerics and priests, worn in Catholic countries on the street as well as indoors. It is worn also by altar servers assisting at ceremonies. Cardinals, bishops, and prelates wear at home a black cassock with red or purple trimmings. The purple cassock is worn in church by bishops and prelates, except on penitential days and a red cassock is worn by cardinals. The pope wears a white cassock.