The cassock, or soutane, is an item of Christian clerical clothing used by the clergy of Catholic, Eastern Orthodox, Anglican and Reformed churches, among others. "Ankle-length garment" is the literal meaning of the corresponding Latin term, vestis talaris. It is related to habit traditionally worn by nuns, monks, and friars. The cassock derives historically from the tunic that in ancient Rome was worn underneath the toga and the chiton that was worn beneath the himation in ancient Greece. In religious services, it has traditionally been worn underneath vestments, such as the alb.