is a specific kind of: fill, fill up, make full.

is a broader term that covers: load down, pack | bomb up | overcharge, overload, surcharge | reload | stack.

derivation: loading | cargo, consignment, freight, lading, load, loading, payload, shipment | burden, load, loading | dock-walloper, dock worker, docker, dockhand, dockworker, loader, longshoreman, lumper, stevedore.