- a person who advocates liberty, especially with regard to thought or conduct.
- a person who maintains the doctrine of free will (distinguished from necessitarian).
- advocating liberty or conforming to principles of liberty.
- maintaining the doctrine of free will.
- a believer in freedom of thought, expression, etc
- philosophy a believer in the doctrine of free willCompare determinism
- of, relating to, or characteristic of a libertarian
n.1789, “one who holds the doctrine of free will” (opposed to necessitarian), from liberty (q.v.) on model of unitarian, etc. Political sense of “person advocating liberty in thought and conduct” is from 1878. As an adjective by 1882. U.S. Libertarian Party founded in Colorado, 1971.