Someone has made a working implementation of WordNet for Drools and posted it to the user mailing list, andI thought others might find it interesting so I've blogged it here. The link below is for the email and contains the paste code.
WordNet is a semantic lexicon for the English language. It groups English words into sets of synonyms called synsets, provides short, general definitions, and records the various semantic relations between these synonym sets. The purpose is twofold: to produce a combination of dictionary and thesaurus that is more intuitively usable, and to support automatic text analysis and artificial intelligence applications. The database and software tools have been released under a BSD style license and can be downloaded and used freely. The database can also be browsed online.