'ARM, n. L. armus, an arm, a shoulder, a wing armus is directly from the Gr. a joint, it would seem to be formed from Gr. to fit.

1. The limb of the human body, which extends from the shoulder to the hand.
2. The branch of a tree, or the slender part of a machine, projecting from a trunk or axis. The limbs of animals are also sometimes called arms.
3. A narrow inlet of water from the sea.
4. Figuratively, power, might, strength as the secular arm. In this sense the word is often used in the scriptures.

To whom is the arm of the Lord revealed. Isaiah 53 .

'ARM, L. armo arma.

1. To furnish or equip with weapons of offense, or defense as, to arm the militia.
2. To cover with a plate, or with whatever will add strength, force, or security as, to arm the hilt of a sword.
3. To furnish with means of defense to prepare for resistance to fortify.

Arm yourselves with the same mind. 1 Peter 4 .

'ARM, To provide with arms, weapons, or means of attack or resistance to take arms as, the nations arm for war.

This verb is not really intransitive in this use, but reciprocal, the pronoun being omitted. The nations arm - for, the nations arm themselves.