Webster's Revised Unabridged Dictionary · 1913

Cowl

Cowl (koul) , noun

[Anglo-Saxon cuhle, cugle, cugele; compare dial. German kogel, gugel, Old French coule, goule; all from Late Latin cuculla, cucullus, from Latin cucullus cap, hood; perh. akin to celare to conceal, cella cell. Compare 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.
4.
(aviation) a removable metal covering for an aircraft engine, providing streamlining to minimize wind resistance; -- also called cowling.
5.
a covering for a chimney or other ventilating shaft functioning to increase the draft.

Cowl , noun

[Compare Old French cuvele, cuvel, dim. of French cuve tub, vat, from Latin cupa. See Cup.]

A vessel carried on a pole between two persons, for conveyance of water. — Johnson