(ärm) noun
1. Anat. a The upper limb of the human body, from the shoulder to the hand or wrist, b The part from the shoulder joint to the elbow joint.
2. The fore limb of vertebrates other than man. ♦ Collateral adjective: brachial
3. An armlike part or appendage.
4 The part in contact with the human arm: arm of a chair.
5. Anything branching out like an arm from the main body, or set apart or considered as a distinct part or branch; a subdivision: an arm of the sea.
6. Naut. a One of the projecting members of an anchor, ending in a fluke, b An end of a spar.
7. Strength to accomplish or aid; might: the arm of the law.
—arm in arm With arms enlaced, as two persons walking together.
—at arm's length At a distance, so as to keep from being friendly or intimate.
—with open arms Cordially; warmly. [OE arm, earm]

(ärm) noun
1. A weapon.
2. A distinct branch of the naval or military service: the air arm.
—v.t.
1. To supply with instruments of warfare; equip, as with weapons or tools.
2. To make secure, as with a protective covering.
—v.i.
3. To supply or equip oneself with weapons or other defensive means.
4. To supply oneself with the means necessary for an undertaking. [See ARMS]