Cowl (koul), n. [AS. cuhle, cugle, cugele; cf. dial. G. kogel, gugel, OF. coule, goule; all fr. LL. cuculla, cucullus, fr. L. cucullus cap, hood; perh. akin to celare to conceal, cella cell. Cf. Cucullate.] 1. A monk's hood; — usually attached to the gown. The name was also applied to the hood and garment together.
What differ more, you cry, than crown and cowl?
Pope.
2. A cowl-shaped cap, commonly turning with the wind, used to improve the draft of a chimney, ventilating shaft, etc.
3. A wire cap for the smokestack of a locomotive.