libertine

The word libertine, which originally meant "freedman" when it appeared in 14th-century English, traces to the Latin libertus, a term that in Roman antiquity identified a slave who had been set free. By the late 1500s, "libertine" had been extended to religious and secular freethinkers; Shakespeare used it to refer to anyone who follows his or her own inclinations. By 1600, though, the term had come to imply that an individual was a little too unrestrained, especially in moral situations. And yes, the Latin root of "libertine" is "liber," the ultimate source of our word liberty.