Wiktionary
arm to the teeth
vb. (context idiomatic English) To equip thoroughly with weapons.
Usage examples of "arm to the teeth".
More than one prowling cat had met its death at their spurs, but only the week before, the Chevalier had nearly lost an arm to the teeth of a mangy dog.
They must arm to the teeth and be ready at all times to defend themselves and the land that Laa had given them.