Cowl (cucullus, cuculla, cucullio.—Ducange, “Gloss.”, s.v.), a hood worn in many religious orders. The name was originally used for a kind of bag in which grocers sold their wares (ibid.), then for an article of dress that was like it in shape.
The lacerna or byrrhus (our cope), the usual cloak for outdoor wear until far into the Middle Ages, had a cowl fixed behind, that could be drawn over the head. So also had the paenula (chasuble—Wilpert, “Gewandung der Christen”, pp. 13, 45, etc.; Braun, “Liturg. Gewandung”, pp. 240, 348). Juvenal (VI, 118) and Martial (XI, 98) refer to the cucullus of the lacerna. Sozomen says that monks covered their heads with a hood called cucullus (H. E., III, xiii), and Palladius tells us the same fact about St. Ephraem and the disciples of Pachomius (Hist. Laus., XIII). Both St. Jerome (Ep. xxii, ad Eustochium) and Cassian (De habitu mon., I, iv) refer to it as part of a monk’s dress. St. Benedict ordered two kinds of cowls for his monks, a warm one for winter and a light one for summer (Regula S. Ben., iv). The cowl became a great cloak with a hood. Benedict of Anagni forbade his monks to wear one that came below the knees (Ardo, Vita Ben. Anian., xl). The Benedictines, Cistercians, and all the old monastic orders now use the cowl, a great mantle with a hood that can be thrown back over the shoulders, as a ceremonial dress for choir; the Franciscans have a smaller hood fixed to their habit; canons wear it on their mozzetta, and bishops and cardinals on the cappa. With the Augustinian and Servites it is still a separate hood not attached to anything. Ducange (sv) says the name is a diminutive of casula—”quasi minor cella”. A cowl fixed to a cloak is still commonly worn in Tyrol, parts of Austria and Hungary, etc. Cucullata congregatio occurs occasionally as a general name for monastic orders (Ducange). The color of the cowl is that of the habit, black among Benedictines, white with the Cistercians, etc.