get someone's back up

Also, get someone's dander up; put or set someone's back up. Make angry, as in Bill's arrogance really got my back up, or The foolish delays at the bank only put her back up. Get one's back up and get one's dander up mean “become angry,” as in Martha is quick to get her dander up. The back in these phrases alludes to a cat arching its back when annoyed, and put and set were the earliest verbs used in this idiom, dating from the 1700s; get is more often heard today. The origin of dander, used since the early 1800s, is disputed; a likely theory is that it comes from the Dutch donder, for “thunder.” Also see get someone's goat; raise one's hackles.