wind sail

[ wind ]

/ wɪnd /

a sail rigged over a hatchway, ventilator, or the like, to divert moving air downward into the vessel.

Origin of wind sail

First recorded in 1715–25

The flaps of the windsail hang dead, the sides of the canvas tube have fallen in like the neck of a skinny old man.

An Ocean Tramp |William McFee
If clear decks are wanted, the windsail is about as inconvenient as it is ugly, and that is saying a great deal.

Scientific American Supplement, No. 1082, September 26, 1896 |Various
There was no suggestion of oppressiveness in the air and a windsail was not necessary to keep the cabin fresh and cool.

In the Track of the Trades |Lewis R. Freeman
The breeze from the windsail blew some of the snuff out of the box into the eyes of Macallan.

The King's Own |Captain Frederick Marryat

The sky to the southward is a jet-black mass of clouds, and the windsail is yawing in a strong, cool breeze.

An Ocean Tramp |William McFee

windsail

/ (ˈwɪndˌseɪl) /

a sail rigged as an air scoop over a hatch or companionway to catch breezes and divert them below

any of the vanes or sails of a windmill