Unitarian
Unitarian , noun
[Compare French unitaire, unitairien, New Latin unitarius. See Unity.]
1.
(Theology) One who denies the doctrine of the Trinity, believing that God exists only in one person; a unipersonalist; also, one of a denomination of Christians holding this belief.
2.
One who rejects the principle of dualism.
3.
A monotheist. [Rare] — Fleming
Unitarian , adjective
Of or pertaining to Unitarians, or their doctrines.