(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.

Common Names:

Name	Pronounced	Usage
Agnesi	['ægnisi]
Cymbeline	SIM-bə-leen (English)	Literature
Dietlinde	deet-LIN-də	German
Aggy	['ædʒi]
Betts	[bets]
Devraj	-	Indian, Hindi