Profligate, as a noun or as an adjective, implies recklessly wasting your money on extravagant luxury. Profligate behavior is a lot of fun, but you'll regret it later — when you get your charge card bill.
Any time someone behaves in a reckless, amoral, or wasteful way, they are engaging in profligate behavior. It usually refers to financial behavior but can cross over to social activity as well. A person who is a slave to their cravings and whose behavior is unrestrained and selfish can be called a profligate. Extravagantly profligate behavior is often wildly fun but usually comes with a heavy price to pay in the morning, both financially and morally.