WordWeb Online

1. The central part of a car wheel (or fan or propeller etc) through which the shaft or axle passes
    
2. A centre of activity, interest, commerce or transportation; a focal point around which events revolve
   "the playground is the hub of parental supervision"; "the airport is the economic hub of the area"

Derived forms: hubs

Type of: center [US], centre [Brit, Cdn], eye, heart [Brit], middle, part, portion

Part of: blower, car wheel, electric fan, propeller, propellor

Encyclopedia: Hub, Martin