-in an object-oriented system, the ability of a class to have multiple superclasses and to inherit methods from all of them -c++, like a family tree
the process of deriving a class from several base classes. it is not allowed in java. however, the alternative, multiple interfaces, is allowed.
class can inherit from more than one parent class; in java, there is multiple inheritance of implementation (implements), but not multiple inheritances of state (extends)