We don't have synonyms for karmathian yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are carpathian, kardashian and sarmatian.
(n) :
Alternative form of Qarmatian. [(historical) A member of a religious group combining elements of the Ismaili Shi'i branch of Islam with Persian mysticism, founded by Hamdan Qarmat and centered in eastern Arabia, where they attempted to establish a utopian republic in 899 CE.]
(n) :
Alternative form of Qarmatian. [(historical) A member of a religious group combining elements of the Ismaili Shi'i branch of Islam with Persian mysticism, founded by Hamdan Qarmat and centered in eastern Arabia, where they attempted to establish a utopian republic in 899 CE.]