Source : Free On-Line Dictionary of Computing

jump trace buffer
     
        (JTB) A feature of some {pipelined} processors (e.g. {Amulet},
        {Pentium}?) which stores the source and destination addresses
        of the last few branch instuctions executed.  When a branch
        instruction is fetched, its source is looked for in the JTB.
        If found, the next instuction fetch will be from the previous
        destination of that branch.  If it turns out that the branch
        shouldn't have been taken this time, then the {pipeline} is
        flushed.  This means that in a {tight loop} it is not
        necessary to flush the {pipeline} every time you jump back to
        the start.
     
        (1994-12-15)