A "wheel hub" is the center part of a wheel where it attaches to the axle. It allows the wheel to rotate smoothly and supports the weight of the vehicle. Full definition
This Replacement Wheel Hub Kit is tested to assure the highest quality product. (carparts.com)
One bag was located in the steering wheel hub, while the other sat in place of the glove compartment on the lower passenger side of the dashboard. (en.wikipedia.org)
The recall is to inspect and fix a possible faulty rear wheel hub in these cars. (cardekho.com)