free-spirited and uninhibited
A yojijukugo describing a person who acts freely without being bound by rules or conventions. Often used positively for creative or independent personalities, but can also imply a lack of restraint.
Many people admire his free-spirited and uninhibited way of life.
He created new art with a free-spirited and uninhibited spirit.
自由奔放 is more common and means 'free and unrestrained,' often used for behavior or lifestyle. 奔放不羈 is a less common yojijukugo with a similar meaning but a more literary or classical feel.
不羈 alone means 'unrestrained' or 'unfettered,' but is rarely used independently. 奔放不羈 combines it with 奔放 (wild, free) for emphasis.
A yojijukugo composed of 奔放 (free, unrestrained) and 不羈 (unfettered, not bridled). The exact historical origin is uncertain, but it follows the pattern of four-character idiomatic compounds used in literary and formal contexts.