Spaghetti Inheritance

/spə-ge-tē in-her-ə-tən(t)s/
n. [encountered among users of object-oriented languages that use inheritance, such as Smalltalk] A convoluted class-subclass graph, often resulting from carelessly deriving subclasses from other classes just for the sake of reusing their code. Coined in a (successful) attempt to discourage such practice, through guilt-by-association with spaghetti code.