Hackle (noun)

1. A feathery fibrous structure on the neck of some birds, especially roosters, used for courtship displays.
2. A row of short feathers on the lower back of a fly used for fly-fishing.

Origin:

Unknown origin but possibly from old english word "heccle" meaning a comb used for carding wool.

Examples:

1. The rooster puffed out his hackles and began to strut.
2. The hackle on the fly helped it to float on the water.
3. The hackle is used to create the illusion of movement in the fly.
4. The hackle on the rooster's neck was a brilliant red color.
5. The hackle on the fly was used to create a realistic look.