vane

tuuliviiri

siipi

ohjaussiiveke puhekieltä A weather vane.
Any of several usually relatively thin, rigid, flat, or sometimes curved surfaces radially mounted along an axis, as a blade in a w:turbine turbine or a sail on a windmill, that is turned by or used to turn a fluid.
puhekieltä The flattened, web-like part of a feather, consisting of a series of barbs on either side of the shaft.
A sight on a sextant or compass.
One of the metal guidance or stabilizing fins attached to the tail of a bomb or other missile.
habit
practice
in vain
(inflection of)
habit (an action done on a regular basis)