This isn't precisely what was asked for, but is a thesaurus workflow. Please don't laugh at the code, I write applescript by copy-tweaking!
Uses thesauras.altervista.org and phyllestein's Alp library.
Enjoy!
https://www.dropbox.com/s/42st1gjf44ggdmv/Thesaurus.alfredworkflow
If anyone makes this nicer/cleaner etc. please let me know.