free and uncontrolled; freewheeling; totally uninhibited
Describes a person or behavior that is completely unrestrained, spontaneous, and free-spirited, often with a positive or neutral connotation. Can be used as a noun or na-adjective.
Many people admire his freewheeling way of life.
The painter moved the brush with total abandon.
自由奔放 is more common and emphasizes freedom and lack of restraint, while 奔放自在 adds a nuance of complete self-direction and spontaneity.
Compound of 奔放 (free, unrestrained) and 自在 (free, at will). The exact historical derivation is uncertain, but the combination reinforces the idea of complete freedom.