WordNet

FrameNet

Methodology for analyzing ontologies based on formal, domain-independent properties of classes (metaproperties): identity, unity, rigidity, dependence
Identity: distinguishing a particular instance of a class from other instances of a class by means of a characteristic property, an identity condition; person carries identity conditions such as having-the-same-fingerprints
Unity: distinguishing the parts of an instance from the rest of the world by means of a unity condition
Rigidity: concerned with what properties are essential; identity through change
Dependence: whether each instance of the class implies the existence of another entity