(one's) back is up
(one's) back is up
One is angry, hostile, defensive, or irritable, often due to a particular cause. John's back is up now. You shouldn't have brought up the subject of college. It's election season, so my dad's back is up all the time.
See also: back, up
Farlex Dictionary of Idioms.
- set (one's) back up
- get (one's) back up
- get back up
- get someone's back up
- get/put somebody's back up
- have (one's) back up
- have back up
- Irish
- get (one's) Irish up
- get (one's) hackles up