Definition of unitarians:
(n) :
A follower of Unitarian Universalism or a similar non-credal religion that originated historically from Christian Unitarianism.
(adj) :
Pertaining to Unitarianism.
(n) :
A member of a political movement advocating a unitary state rather than a federal one, especially the Unitarios of nineteenth century Argentina (known as the Unitarian Party in English).
(n) :
(Christianity) A Christian who denies the doctrine of the Trinity, usually stressing some distinctions between God the Father and God the Son without denying the divinity of Jesus.
(n) :
(Islam) Synonym of Muwahhid, a Muslim advocating God's strict unity.
(n) :
(uncommon) Synonym of monotheist, a believer in the unity of God, particularly non-Christians (Muslims, Jews, etc.) discussed from a Christian perspective.