HUB

[noun] [C] - the central part of a wheel into which the spokes (= bars connecting the central part to the outer edge of the wheel) are fixedThe hub of my bicycle wheel has rusted.The hub of something is the central or main part where there is most activity.The airline's hub is in St Louis.The computer department is at the hub of the company's operations.The City of London is the hub of Britain's financial world.