放荡 is a harsh, judgmental word, especially when directed at women. 放荡不羁 (fàngdàng bùjī) is a set phrase meaning 'wild and unrestrained' that can carry a more romantic, literary tone — think of a free-spirited poet.
usage
Contrast with 开放 (kāifàng, open-minded) which is neutral/positive. 放荡 is always negative or at best edgy-literary.
