Largest and most comprehensive thesaurus
  1 review

Moby Thesaurus is the largest and most comprehensive thesaurus data source in English available for commercial use. This second edition has been thoroughly revised adding more than 5,000 root words (to total more than 30,000) with an additional _million_ synonyms and related terms (to total more than 2.5 _million_ synonyms and related terms).

This is formatted for use by the dictionary server in the dictd package.
Latest reviews
MagicMint 7 years ago

It’s really comprehensive, and it integrates well with goldendict.