Vane - Definition

n 1: mechanical device attached to an elevated structure;
rotates freely to show the direction of the wind [syn:
weathervane, weather vane, vane, wind vane]
2: a fin attached to the tail of an arrow, bomb or missile in
order to stabilize or guide it
3: flat surface that rotates and pushes against air or water
[syn: blade, vane]
4: the flattened weblike part of a feather consisting of a
series of barbs on either side of the shaft [syn: vane,
web]