Source : Free On-Line Dictionary of Computing

derived class
     
         (Or "subclass") In {object-oriented}
        programming, a {class} that is derived from a {base class} by
        {inheritance}.  The derived class contains all the features of
        the base class, but may have new features added or redefine
        existing features.
     
        The synonym "subclass" is possibly confusing since the derived
        class has a superset of the base class's features.
     
        Compare {derived type}.
     
        (2001-09-14)