From the README:

WordNet::QueryData provides a direct interface to the WordNet database files.
It requires the WordNet package (http://www.cogsci.princeton.edu/~wn/).  It
allows the user direct access to the full WordNet semantic lexicon.  All parts
of speech are supported and access is generally very efficient because the
index and morphical exclusion tables are loaded at initialization.  This
initialization step is slow (appx. 10-15 seconds), but queries are very fast
thereafter---thousands of queries can be completed every second.

WWW: http://www.ai.mit.edu/people/jrennie/WordNet/