Vane
Vane (vān) , noun
[Old English & Prov. English fane weathercock, banner, Anglo-Saxon fana a banner, flag; akin to Dutch vaan, German fahne, Old High German fano cloth, gund fano flag, Icelandic fāni, Swedish fana, Danish fane, Gothic fana cloth, Latin pannus, and perhaps to Greek ph^nos a web, phni`on a bobbin, spool. Compare Fanon, Pane a compartment, panel.]
1.
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.
Aye undiscreet, and changing as a vane.
2.
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.
3.
(Zoology) The rhachis and web of a feather taken together.
4.
One of the sights of a compass, quadrant, etc.