Source : Free On-Line Dictionary of Computing

secondary cache
     
         (Or "second level cache", "level two
        cache", "L2 cache") A larger, slower {cache} between the
        {primary cache} and main memory.  Whereas the primary cache is
        often on the same {integrated circuit} as the {central
        processing unit} (CPU), a secondary cache is usually external.
     
        (1997-06-25)