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The cassock, also known as a soutane, is a long, sheath-like, close fitting, ankle length robe worn by Christian celebrants of various denominations, including Anglicans and Roman Catholics. The cassock derives ultimately from the tunic that was formerly worn underneath the toga in classical antiquity. It comes in a number of colours, which have traditional meanings. The ordinary priest's cassock is black. Bishops traditionally wear purple ones; cardinals, of course, get red ones, and the Pope's cassock is white. In tropical climates, ordinary priests frequently wear white cassocks.The cassock comes in a number of styles, though no particular symbolism attaches to these. A Roman cassock has many buttons down the front; a French cassock has fewer front buttons, but buttons sewn to the sleeves after the manner of a suit, and a broader skirt. A Jesuit cassock has a fly fastened with hooks.Cassocks are sometimes worn by lay people when they are assisting with the liturgy in church. In most Western countries, the clergy have generally abandoned the cassock as everyday clothing in favour of a clerical suit of more conventional design.

A black garment reaching down to the ankles; worn by priests or choristers.