This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
A messiah was a title for an individual who had, or was believed to have, the power to save a people, group, or members of a religion from some calamity.
In 2377, after learning that his daughter could be the prophesied kuvah'magh, Tom Paris remarked to B'Elanna Torres, " I was hoping our daughter would be special, but I never dreamed she'd turn out to be the Klingon messiah." Torres didn't appreciate his comments, fearing the child's life might be in danger. (VOY: "Prophecy")