a person who is unrestrained by convention or morality; specif a person who leads a dissolute life
It is easier to make a saint out of a libertine than out of a prig — George Santayana
a freethinker, esp in religious matters
libertinage /-nij/ noun
libertine adj
libertinism /-tiniz(ə)m/ noun
[Middle English libertyn freedman, from Latin libertinus of a freedman, from libertus freedman, from liber free]