- a flat piece of metal, strip of cloth, etc. set up high to swing with the wind and show which way it is blowing; weather vane
- any of several flat or curved pieces set around an axle and rotated about it by moving air, water, etc. [the vanes of a windmill], or mechanically rotated to move the air or water [the vanes of a turbine] or to compress the air [the vanes of a supercharger]
- a projecting fixed or movable plate or strip of metal attached to a rocket, missile, etc. to provide stability or guidance
- a target set to slide on a leveling rod, for use in surveying
- any of the sights on a compass, quadrant, etc.
- the flat part of a feather with barbs; web
- a feather on an arrow, used to stabilize flight
Origin of vanesouthern British variant, variety of fane, small flag or pennon from Old English fana, a flag from Proto-Germanic an unverified form fanan- from Indo-European base an unverified form pan- from source pane