vane

nouns

mechanical device attached to an elevated structure; rotates freely to show the direction of the wind
vane, weather vane, weathervane, wind vane
a fin attached to the tail of an arrow, bomb or missile in order to stabilize or guide it
vane
is a part of
a projectile with a straight thin shaft and an arrowhead on one end and stabilizing vanes on the other; intended to be shot from a bow
arrow
is a part of
a rocket carrying a warhead of conventional or nuclear explosives; may be ballistic or directed by remote control
missile
is a type of (narrower)
a stabilizer on a ship that resembles the fin of a fish
fin
flat surface that rotates and pushes against air or water
blade, vane
the flattened weblike part of a feather consisting of a series of barbs on either side of the shaft
vane, web