unitarist

As an adjective unitarist

is of or pertaining to unitarianism.

As a noun pluralist is

a person who holds multiple offices, especially a clergyman who holds more than one ecclesiastical benefice.

As a noun unitarianism

is the belief in a single God, not divided into any aspects, particularly when presented as a contrast to Christian trinitarianism.

As a proper noun Unitarianism

is (beginning in 1961) The religion known as Unitarian Universalism.

As an adjective unitarist is

of or pertaining to Unitarianism.