hack ‧ les /ˈhæk ə lz/ BrE AmE noun [plural]
[ Date: 1400-1500 ; Origin: Probably from an unrecorded Old English hacule 'small hook' ]
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 heard his remark, and felt her hackles rising.
raise sb’s hackles (=make someone angry)
His tactless remarks 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