Source : Webster's Revised Unabridged Dictionary (1913)

Jujutsu \Ju"jut`su\, n. Also Jujitsu \Ju"jit`su\, Jiujutsu
\Jiu"jut`su\, Jiujitsu \Jiu"jit`su\ [Jap. j[=u]jutsu; j[=u] soft
   (prob. because no weapons are used) + jutsu art.]
   The Japanese art of self-defense without weapons, now widely
   used as a system of physical training. It depends for its
   efficiency largely upon the principle of making use of an
   opponent's strength and weight to disable or injure him, and
   by applying pressure so that his opposing movement will throw
   him out of balance, dislocate or break a joint, etc. It
   opposes knowledge and skill to brute strength, and demands an
   extensive practical knowledge of human anatomy.

Source : WordNet®

jujutsu
     n : a method of self-defense without weapons that was developed
         in China and Japan; holds and blows are supplemented by
         clever use of the attacker's own weight and strength
         [syn: {jujitsu}, {jiujitsu}]