(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
Telmo	-	Portuguese, Spanish
Kalyn	KAY-lin	English (Modern)
Ward	WAHRD	English
Camellia	kə-MEEL-ee-ə, kə-MEL-ee-ə	English (Rare)
Reene	-	English (Rare)
Melek (1)	-	Hebrew