From Longman Dictionary of Contemporary Englishhackleshack‧les /ˈhækəlz/ noun [plural] 1 → somebody’s hackles rise2 HBAHBBthe long feathers or hairs on the back of the neck of some animals and birds, which stand up straight when they are frightened or ready to fight
Examples from the Corpus
hackles• The script fits Steve Forbes, whose self-financed run for the Republican presidential nomination is raising hopes and hackles.• She felt defensive hackles rise on the back of her neck.• Both sexes may erect hackles on neck when alarmed, to form prominent whiskers.• I think documenting would only get his hackles raised further.• But something has happened to raise our hackles.• In the United States, the mere idea raises hackles.Origin hackles (1400-1500) Probably from an unrecorded Old English hacule “small hook” 