Way to extract Google Synonyms

Question

Hello,

Would anyone know of a way to extract Google Synonyms, either through their API or other (TOS-approved) methods?

Specifically, Google have a function that allows you to type a tilde sign "~" in front of a word to conduct a search with synonyms.

As opposed to the search results, I'd like to extract the actual synonym data - so for ~cat, I would like a script that returns feline, kitten, etc.

http://www.synonymlab.com/ do something similar, I guess - but do they do this through the API?

Sorry but there's limited information out there. Any ideas if it's possible?

Thanks,

P.