Longman Dictionary of Contemporary English - hackles

~ n plural 1 sb's hackles rise if someone's hackles rise they begin to feel very angry, because someone's behaviour or attitude offends them  (Laura saw the insolent look on his face, and felt her hackles rising. | raise sb's hackles (=make someone angry))  (tactless remarks that were enough to raise anyone's hackles) 2 the long feathers or hairs on the back of the neck of some animals and birds, which stand up straight when they are in danger