(n.) A contrivance attached to some elevated object for the
purpose of showing which way the wind blows; a weathercock. It is
usually a plate or strip of metal, or slip of wood, often cut into some
fanciful form, and placed upon a perpendicular axis around which it
moves freely.
(n.) Any flat, extended surface attached to an axis and moved by
the wind; as, the vane of a windmill; hence, a similar fixture of any
form moved in or by water, air, or other fluid; as, the vane of a screw
propeller, a fan blower, an anemometer, etc.
(n.) The rhachis and web of a feather taken together.
(n.) One of the sights of a compass, quadrant, etc.
