This WordNet module (WordNet::QueryData) is a Perl interface to the WordNet database. WordNet is a database of word meanings and lexical relationships. It contains tens of thousands of words and numerous semantic relationships for each. For example, it can tell you that a limousine is a type of a car and that a car is a type of motor vehicle. It can also tell you that car and automobile have essentially the same meaning.

via WordNet Perl Module.