Definition of hackles in English English dictionary
If something raises your hackles or makes your hackles rise, it makes you feel angry and hostile
{i} erectile hairs on the back of animals; feathers on the back of the neck of birds that rise when the bird is scared or is just about to fight; feeling of anger; feeling of hostility; dander
By extension (because the hackles of a cock are lifted when it's angry), the hair on the nape of the neck in dogs and other animals; also used figuratively for humans
When the dog got angry his hackles rose and he growled.
One of the peculiar, long, narrow feathers on the neck of fowls, most noticeable on the cock, often used in making artificial flies; hence, any feather so used