Licentious is an adjective describing people or conduct that does not adhere to rules or standards. Originally, the term referred to flouting the rules of the English language. However, today it is commonly used to describe people or acts without moral compass or restraint, especially regarding sexual behavior.
Licentious comes from the Latin term licentiousus, from licentia, which translates to license or freedom. It was common in the 1700s, but is more likely to be replaced with a word like promiscuous today.