WordWeb is an English pop-up dictionary, thesaurus and word finder, free for
personal use. It includes a comprehensive English thesaurus and dictionary,
and can be used to look up words from within most programs. Features of the
free version include: Definitions and synonyms, Proper nouns, Related words,
Pronunciations, 150,000 root words, 120,000 synonym sets. (in Business and
Productivity)