libertine

Short definition from Wiktionary

Noun

1. 1
   Someone freed from slavery in Ancient Rome; a freedman.
2. 2
   One who is freethinking in religious matters.
3. 3
   Someone (especially a man) who takes no notice of moral laws, especially those involving sexual propriety; someone loose in morals; a pleasure-seeker.

Adjective

1. 1
   Dissolute, licentious, profligate; loose in morals.