hackle (n.)

Old English hacele "coat, cloak, vestment, mantle" (cognate with Old High German hachul, Gothic hakuls "cloak;" Old Norse hekla "hooded frock"), of uncertain origin. The same word with a sense of "bird plumage" is first recorded early 15c., though this might be from unrelated Middle English hackle "flax comb" (see heckle (n.)) on supposed resemblance of comb to ruffled feathers, or from an unrecorded continental Germanic word. Metaphoric extension found in phrases such as raise (one's) hackles (as a cock does when angry) is by 1881.

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Definitions of hackle from WordNet
hackle (v.)
comb with a heckle;
Synonyms: heckle / hatchel
hackle (n.)
long slender feather on the necks of e.g. turkeys and pheasants;