Make one very angry, as in That really raised my hackles when he pitched straight at the batter's head. Hackles are the hairs on the back of an animal's neck, which stick up when the animal feels fearful or angry. [Late 1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.