Source : WordNet®

knowledge base
     n : the content of a particular domain or field of knowledge
         [syn: {knowledge domain}]

Source : Free On-Line Dictionary of Computing

knowledge base
     
         A collection of {knowledge}
        expressed using some formal {knowledge representation}
        language.  A knowledge base forms part of a {knowledge-based
        system} (KBS).
     
        (1994-10-19)