What does "unitarianism" mean?

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

What is a synonym for "unitarianism"?

Common synonyms include: denomination.

name, noun

name, noun ·Rare ·Advanced level

Noun

1
The belief in a single God, not divided into any aspects, particularly when presented as a contrast to Christian trinitarianism. countable, uncountable
"Some New England congregations embraced Unitarianism (the belief in a unitary God as opposed to a holy trinity), and some of those moved on to Unitarian Universalism[.]"
2
A Christian theology that God has one part, rather than the three equal parts (Father, Son, and Holy Spirit) posited by Trinitarianism. uncountable
3
a non-doctrinal religion that stresses individual freedom of belief and rejects the Trinity wordnet

Proper Noun

1
The religion known as Unitarian Universalism.
2
Any of various Christian denominations such as the Unitarian Church of Transylvania, General Assembly of Unitarian and Free Christian Churches and American Unitarian Association.