noun

• (Abrahamism) The one who is ordained by God to lead the people of Israel, believed by Christians and Muslims to be Jesus Christ.
• (religion, loosely) A similar religious figure or awaited divine ruler, such as the Islamic Mahdi.
  "The spice exists on only one planet in the entire universe- a desolate, dry planet with vast deserts. Hidden away within the rocks of these deserts are a people known as the Fremen, who have long held a prophecy, that a man would come, a messiah, who would lead them to true freedom. The planet is Arrakis, also known as Dune."
• (figuratively) An extremely powerful or revered figure.
  "At its best, psychoanalysis is the classic therapeutic technique for exploring unconscious processes. At its less-than-best, it is a jargon-opacified oedipus-complicated, libido-theoretical, pseudo-scientific cult whose messiah is Sigmund Freud."

name

• (Judaism) The promised and expected savior or liberator of the Jewish people.
• (Christianity) Jesus Christ.