libertarian Noun One who advocates liberty either generally or on a specific issue, e.g. "civil libertarian" (in favour of civil liberties).
libertarian Noun A believer in a political doctrine that emphasizes individual liberty and a lack of governmental regulation and oversight both in matters of the economy ('free market') and in personal behavior where no one's rights are being violated or threatened. Also 'classical liberal', akin to 'anarcho-capitalist'.
libertarian Noun An anarchist, typically with socialist implications.
libertarian Noun In the philosophy branch of metaphysics, a believer in thinking beings' freedom to choose their own destiny, i.e. a believer in free will as opposed to those who believe the future is predetermined.
libertarian Noun a member of the Republican Party (especially a legislator) who emphasizes economic and Constitutional, rather than religious and personal, aspects of the party's platform.
libertarian Adjective Relating to the beliefs of libertarians, as in, "He has "libertarian" views". A relative tendency towards liberty, as in "libertarian" capitalist".