leather garment
韍 refers to a leather garment, specifically a knee-covering or apron-like piece worn in ancient times.
韍 combines 韋 (leather) with 犮, which likely contributes a phonetic element. The character is rare and its exact historical development is uncertain.
The left side 韋 means leather, and the right side 犮 looks like a person kneeling with a covering. Imagine a leather apron tied around the waist, hanging down to protect the knees.
For フツ, picture putting on a leather apron and hearing the soft 'futs' sound as it settles into place: futs -> フツ.