org.apache.lucene.wordnet (Lucene 2.2.0 API)

This package uses synonyms defined by WordNet to build a Lucene index storing them, which in turn can be used for query expansion.

Class Summary
SynExpand	Expand a query by looking up synonyms for every term.
SynLookup	Test program to look up synonyms.
Syns2Index	Convert the prolog file wn_s.pl from the WordNet prolog download into a Lucene index suitable for looking up synonyms and performing query expansion (`SynExpand.expand(...)`).

Package org.apache.lucene.wordnet Description:

This package uses synonyms defined by WordNet to build a Lucene index storing them, which in turn can be used for query expansion. You normally run Syns2Index once to build the query index/"database", and then call SynExpand.expand(...) to expand a query.

Instructions

Download the WordNet prolog database , gunzip, untar etc.
Invoke Syn2Index as appropriate to build a synonym index. It'll take 2 arguments, the path to wn_s.pl from that WordNet downlaod, and the index name.
Update your UI so that as appropriate you call SynExpand.expand(...) to expand user queries with synonyms.