Synonyms Database Wanted

Which Raw Files Have Worked Best For You?

[Tigrou]

I am looking for "the best" synonyms database that folks have run across and, ideally, tried.

I have absolutely no interest in the interface -- I just want the raw files (col 1 = word/phrase, col 2 = related words/phrases) for a project. Best if it carries both US & British English Phrases.

Many thanks for your feedback,
Colin