noun 1.( often initial capital letter ) the belief in the coming of the Messiah, or a
movement based on this belief.
2.the belief in a leader, cause, or ideology as a savior or deliverer.
Origin: 1875–80; <
Late Latin Messīān-, stem of
Messīās Messiah +
-ism Related forms mes·si·a·nist, Mes·si·a·nist, noun