barbule

noun

1. a small barb.
2. any of the small processes fringing the barbs of a feather.

noun

1. a very small barb
2. ornithol any of the minute hairs that project from a barb and in some feathers interlock by hooks and grooves, forming a flat vane

1. A small barb or pointed projection, especially one that fringes the edges of the barbs of feathers.