A close-fitting robe with long sleeves worn by clergy in ordinary life and by clergy and laymen as well when taking part in religious functions. This name was originally given to the dress of soldiers and horsemen but survives today in ecclesiastical use only.
The ordinary cassock varies in color and trim, as a signification of different degrees of ecclesiastical dignity: that of the pope is entirely white without trimmings of any color; that of cardinals is black trimmed with scarlet; that of archbishops and bishops is black trimmed with amaranth red, and that of pastors and curates is black without any trim.
The cassock reserved for choir and public ceremonies of the Church is more colorful but without contrasting trim. The pope wears white silk. Scarlet is worn by cardinals at ordinary times, and purple in penitential season. Bishops wear purple, and pastors retain black. Laymen wear black when they are permitted to take the place of those in the minor orders of the clergy. The use of red for the cassock of laymen dates from the 19th century and should not be tolerated.
cas·sock / ˈkasək/ • n. a full-length garment of a single color worn by certain Christian clergy, members of church choirs, acolytes, and others having some particular office in a church. DERIVATIVES: cas·socked adj.