Overview
A cowl is an item of clothing consisting of a long, hooded garment with wide sleeves, often worn by monks.
Originally it may have referred simply to the hooded portion of a cloak. In contemporary usage, however, it is distinguished from a cloak or cape (cappa) by the fact that it refers to an entire closed garment. Today it is worn primarily by most Catholic and Anglican monks when participating in liturgical services.
Religious usage
Developed during the Early Middle Ages, it became the formal garment for those in monastic life. Both St. Jerome and John Cassian refer to it as part of a monk's dress. In modern times, it is worn over the habit during liturgical services.
Among the Benedictines, in choir, at chapter, and at certain other ceremonial times, a long full gown with large flowing sleeves, called a "cowl", is worn over the ordinary habit. Black has been the prevailing color, hence the term "black monk" has come to signify a Benedictine. Previous generations had lengthened the garment until it reached to the heels, and Saint Benedict issued a rule restricting its length to two cubits.
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