From Longman Dictionary of Contemporary EnglishUnitarianU‧ni‧ta‧ri‧an /ˌjuːnəˈteəriən $ -ˈter-/ noun [countable] RRCa member of a Christian group that does not believe in the Trinity —Unitarian adjective
Examples from the Corpus
Unitarian• Even Jefferson sometimes allowed himself to be called a Unitarian.• No studious Unitarian cushioned in a Boston study had a chance of winning the West against such a spirit. 