a truncated cloth cone mounted on a mast; used (e.g., at airports) to show the direction of the wind

a cone-shaped bag with an opening at both ends

a device that shows which way the wind is blowing and the wind's speed

Other expression for: wind direction indicator

a device used to show the direction of the wind and to some extent the wind speed; useful for take-offs and landings

A windsock is a large, conical, tube designed to indicate wind direction and relative wind speed. Windsocks typically are used at airports and in chemical plants in which there is risk of gaseous leakage. They are sometimes located alongside highways at windy locations.