A title for the character Paul Atreides, from Frank Herbert's Dune.
The result of the Bene Gesserit Mating Index. Paul Atreides did not rise to this status by drinking the Water of Life, per se.
The Kwisatz Haderach is the person who could be many places at once, the universe's super-being. The Bene Gesserit had been searching for the Kwisatz Haderach for ninety generations, and knew (believed) that if they gave this man the Water of Life, he would be able to see down both the feminine and masculine parts of his past, and be something of a super-mentat as well.
Paul came one generation too early (according to the BG Mating Index, which called for 90 generations of breeding, Paul was 89th in line), and set off the events of the first three of the Dune Chronicles. He was not the right man. He was right, according to the book. He was a freak.