hub /ˈhʌb/ noun
1 . the central and most active part or place
- the hub of the city
- The island is a major tourist hub. [=a place where many tourists go]
- She was at the hub of all the activity.
2 . the airport or the city through which an airline sends most of its flights
- All of the airline’s coast-to-coast flights pass through its hub.
3 . the center of a wheel, propeller, fan, etc.
- The spokes attach to the hub of the wheel.