1. recklessly wasteful; wildly extravagant 2. completely given up to dissipation and licentiousness

This word can be found in Kate Atkinson’s Case Histories, which I’m reading at the moment: When she was smaller Julia had been subject to the most profligate tantrums, and even now a day rarely went by without Julia having a hysterical fit over something or other and flouncing out of a room.