Cowl (through Fr. coule, from Lat. cucullus or cuculla, a covering; the word is found in various forms in most European languages, cf. Ger. Kugel or Kigel, Dutch kovel, Irish cochal or cochull; the ultimate origin may be the root kal, found in Lat. clam, secretly, and Gr. καλύπτειν, to hide, cover up), an outer garment worn by both sexes in the middle ages; a part of the monastic dress, hence the phrase “to take the cowl,” signifying entry upon the religious life. The cucullus worn by the early Egyptian anchorites was a hood covering the head and neck. Later generations lengthened the garment until it reached to the heels, and St Benedict issued a rule restricting its length to two cubits. Chapter 55 of his Institute prescribes the following dress in temperate climates: a cowl and tunic, thick in winter and thin in summer, with a scapular for working hours and shoes and stockings, all of simple material and make. In the 14th century the cowl and the frock were frequently confounded, but the council of Vienne defined the former as “a habit long and full without sleeves,” and the latter as “a long habit with long and wide sleeves.” While the term thus seems strictly to imply a hooded gown it is often applied to the hood alone. It is also used to describe a loose vestment worn over the frock in the winter season and during the night office.
The word “cowl” is also applied to a hood-shaped covering to a chimney or ventilating shaft, to help down-draught, and to clear the up-current of foul air (see Ventilation).