Jujutsu (English pronunciation: /dʒuˈdʒʌtsu/; Japanese: 柔術, jūjutsu  listen (help·info), Japanese pronunciation: [ˈdʑɯɯ.dʑɯ.tsɯ]) is a Japanese martial art and a method of close combat for defeating an armed and armored opponent in which one uses no weapon, or only a short weapon. The word jujutsu is often spelled as jujitsu, ju-jitsu or jiu-jitsu, this is due to the difficulties in translating the Japanese writing system, which uses ideograms, to languages which use an alphabet. When the martial art spread to foreign countries the word jujutsu was adopted to describe it, although in many cases the romanization wasn't known at the time of adoption so it was written down phonetically.

"Jū" can be translated to mean "gentle, supple, flexible, pliable, or yielding." "Jutsu" can be translated to mean "art" or "technique" and represents manipulating the opponent's force against himself rather than confronting it with one's own force. Jujutsu developed among the samurai of feudal Japan as a method for defeating an armed and armored opponent in which one uses no weapon, or only a short weapon. Because striking against an armored opponent proved ineffective, practitioners learned that the most efficient methods for neutralizing an enemy took the form of pins, joint locks, and throws. These techniques were developed around the principle of using an attacker's energy against him, rather than directly opposing it.