Reanimation is a term used when someone is brought back to life. Reincarnation is often used as well. The most famous use for "reanimation" is the Summoning Jutsu: Reanimation, aka the Summoning: Impure World Reincarnation. The original name being of course Kuchiyose: Edo Tensei. In this jutsu a dead person is "reanimated" and summoned back to the world of Naruto, the person is referred to Reanimated ***** after this point, such as Reanimated Itachi or Reanimated Madara, or if you prefer Reincarnated Madara or Edo Tensei Itachi.