n.
Function: noun
Usage: often attrib
Etymology: Middle English armes (pl.) weapons, from Anglo-French, from Latin arma
Date: 13th century
1 a : a means (as a weapon) of offense or defense especially : FIREARM b : a combat branch (as of an army) c : an organized branch of national defense (as the navy)
2 plural a : the hereditary heraldic devices of a family b : heraldic devices adopted by a government
3 plural a : active hostilities : WARFARE <a call to arm s > b : military service
– up in arms : aroused and ready to undertake a fight or conflict <voters up in arms over the proposed law>