Source : Webster's Revised Unabridged Dictionary (1913)

Arm \Arm\, v. t. [imp. & p. p. {Armed}; p. pr. & vb. n.
   {Arming}.] [OE. armen, F. armer, fr. L. armare, fr. arma,
   pl., arms. See {arms}.]
   1. To take by the arm; to take up in one's arms. [Obs.]

            And make him with our pikes and partisans A grave:
            come, arm him.                        --Shak.

            Arm your prize; I know you will not lose him. --Two
                                                  N. Kins.

   2. To furnish with arms or limbs. [R.]

            His shoulders broad and strong, Armed long and
            round.                                --Beau. & Fl.

   3. To furnish or equip with weapons of offense or defense;
      as, to arm soldiers; to arm the country.

            Abram . . . armed his trained servants. --Gen. xiv.
                                                  14.

   4. To cover or furnish with a plate, or with whatever will
      add strength, force, security, or efficiency; as, to arm
      the hit of a sword; to arm a hook in angling.

   5. Fig.: To furnish with means of defense; to prepare for
      resistance; to fortify, in a moral sense.

            Arm yourselves . . . with the same mind. --1 Pet.
                                                  iv. 1.

   {To arm a magnet}, to fit it with an armature.

Armed \Armed\, a.
   1. Furnished with weapons of offense or defense; furnished
      with the means of security or protection. ``And armed
      host.'' --Dryden.

   2. Furnished with whatever serves to add strength, force, or
      efficiency.

            A distemper eminently armed from heaven. --De Foe.

   3. (Her.) Having horns, beak, talons, etc; -- said of beasts
      and birds of prey.

   {Armed at all points} (Blazoning), completely incased in
      armor, sometimes described as {armed cap-[`a]-pie}.
      --Cussans.

   {Armed en flute}. (Naut.) See under {Flute}.

   {Armed magnet}, a magnet provided with an armature.

   {Armed neutrality}. See under {Neutrality}.

Source : WordNet®

armed
     adj 1: (used of persons or the military) characterized by having or
            bearing arms; "armed robbery" [ant: {unarmed}]
     2: having arms or arms as specified; used especially in
        combination; "the many-armed goddess Shiva" [ant: {armless}]
     3: used of plants and animals [ant: {unarmed}]