DuckCorp Dico

Found one definition

1.                 From The Collaborative International Dictionary of English v.0.48:
                   
   
   
                   
                     
   CB \CB\ n.
      same as citizens' band; that portion of the radio frequency
      spectrum allocated by the FCC for the use of individual
      citizens for short-distance personal or business use, from
      either fixed or mobile stations. Also used attributively, as
      CB radio. [acronym]
      Syn: Citizens' Band.
           [PJC]