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the lamellar part of a bird’s feather that lies on both sides of the shaft. It consists of numerous flattened formations, or barbs, that project from the shaft. Each barb has two rows of small lamellae, or barbules, equipped with hooked projections, or barbicels. The barbicels hook adjacent barbs tightly together, forming an elastic, air-resistant surface.
ii. A fixed or movable surface used to control or give stability to a rocket or a missile.
iii. A blade or paddlelike object, often fashioned like an airfoil and usually one of several, that rotates about an axis, either being moved by a flow or creating a flow itself, such as the blade of a turbine, a fan, a rotary pump, an air compressor, etc.
iv. Any of certain stationary blades, plates, or the like that serve to guide or direct a flow, or to create a special kind of flow, as in (i) any of the blades in the nozzle ring of a gas turbine engine; (ii) any of the plates or slatlike objects that guide the flow in a wind tunnel; or (iii) a plate or fence projecting from a wing to prevent a span-wise flow. See nozzle guide vanes.
v. A bomb-arming vane. When a bomb is released from the aircraft, the vanes start rotating and, after a predetermined period, arm the bomb.
vi. A weather vane. A device that shows the direction in which the wind is blowing. See weather vane.