Source : Webster's Revised Unabridged Dictionary (1913)

Unarmed \Un*armed"\, a. [Pref. un- not + armed.]
   1. Not armed or armored; having no arms or weapons.

   2. (Nat. Hist.) Having no hard and sharp projections, as
      spines, prickles, spurs, claws, etc.

Source : WordNet®

unarmed
     adj 1: (used of persons or the military) not having or using arms;
            "went alone and unarmed"; "unarmed peasants were shot
            down"; "unarmed vehicles" [ant: {armed}]
     2: used of plants or animals; without barbs or stings [ant: {armed}]