Hub \Hub\ (h[u^]b), n. [See 1st Hob.]
   1. The central part,
         usually cylindrical, of a wheel; the
      nave. See
         Illust. of Axle box.
 
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   2. The
         hilt of a weapon. --Halliwell.
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         3. A rough protuberance or projecting obstruction; as, a
         hub
      in the road. [U.S.] See Hubby.
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         Webster]

   4. A goal or mark at which quoits, etc., are
         cast.
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   5. (Diesinking) A
         hardened, engraved steel punch for
      impressing a
         device upon a die, used in coining, etc.
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         Webster]

   6. A screw hob. See Hob, 3.
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         Webster]

   7. A block for scotching a wheel.
     
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   8. The central location within which
         activities tend to
      concentrate, or from which
         activities radiate outward; a
      focus of activity.
   
           [PJC]

   9. Hence: (Aeronautics) A large airport used
         as a central
      transfer station for an airline,
         permitting economic air
      transportation between remote
         locations by directing
      travellers through the hub,
         often changing planes at the
      hub, and thus keeping
         the seat occupancy rate on the
      airplanes high. The
         hub together with the feeder lines
      from remote
         locations constitute the so-called

   {hub and spoke
         system} of commercial air passenger
      transportation. A
         commercial airline may have more than
      one such hub.

              [PJC]

   10. The city of Boston, Massachusetts
         referred to locally by
       the nickname The Hub.
    
           [PJC]

   Hub
         plank (Highway Bridges), a horizontal
         guard plank along
      a truss at the height of a
         wagon-wheel hub.

   Up to the hub, as far as possible
         in embarrassment or
      difficulty, or in business, like
         a wheel sunk in mire;
      deeply involved. [Colloq.]
   
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