This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
骲 combines 骨 (bone) with 包 (wrap). The exact historical development is uncertain, but it likely relates to a bone-related object or tool, possibly an arrowhead made of bone, as suggested by the kun reading やじり.
The left side 骨 means bone, and the right side 包 means wrap. Picture a bone wrapped around something, perhaps an arrowhead made of bone.
For ハク, imagine a bone arrowhead being hacked into shape: hack -> ハク, and the bone is wrapped tightly.