Wordnet at Princeton University has developed a program for highlighting and linking words in text documents to there online dictionary. I am not sure exactly how it works but it works good. Maybe some bright person here could write a hack to use this tool in Xoops. Here is the link where you can see how it works.

http://poetry.tetto.org/define/19720/

If anyone has any ideas how to get this done please let me know I can try to help.

James