to walk alone, self-reliant
偊 centers on solitary, independent movement: walking alone and being self-reliant. The two given meanings are closely linked by the idea of acting without company or support.
偊 combines the person radical 亻 with 禹, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with solitary walking and self-reliance.
A person 亻 beside the unusual shape 禹: picture a lone figure walking a winding, solitary path, relying only on themselves.
For ウ, imagine a person walking alone making a soft 'oo' sound of solitude: oo -> ウ, as they step forward self-reliantly.