A set of classes and their interrelationships. One class may be a specialisation (a "subclass" or "{derived class}") of another which is one of ITs "{superclasses}" or "base classes". When a method is invoked on an objectIT is first looked for in the object' s class, then the superclass of that class, and so on up the hierarchy until IT is found. Thus a class need only define those methods which are specific to IT, and inherITs methods from all ITs superclasses. See also: multiple inherITance. (1997-08-06)