Definition of "unitarian"

Espousing a unitary view of something  examples

(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.  examples

(Islam) Synonym of Muwahhid, a Muslim advocating God's strict unity.  examples

(uncommon) Synonym of monotheist, a believer in the unity of God, particularly non-Christians (Muslims, Jews, etc.) discussed from a Christian perspective.  examples

A person who rejects dualism in other contexts.  examples