up in arms

up in arms  {adj. phr.}
1. Equipped with guns or weapons and ready to fight.
All of the colonies were up in arms against the Redcoats.
Syn.: IN ARMS.
2. Very angry and wanting to fight.
Robert is up in arms because John said he was stupid.
The students were up in arms over the new rule against food in the dormitory.
Categories: adjective

'up in arms' on video