suitcase, bag, briefcase
鞄 centers on a portable container made of leather or similar material: a suitcase, bag, or briefcase for carrying personal items.
鞄 combines 革 (leather) with 包 (wrap, bundle), suggesting a leather container that wraps or holds items. The exact historical development is uncertain, but the component combination fits the meaning of a bag or case.
Leather 革 wraps around 包, like a leather bag that bundles your belongings inside. Picture a sturdy leather briefcase with a secure wrap closure.
For ハク, imagine packing a bag for a hike: hike -> ハク, and your leather bag holds everything you need.