I am looking for English Thesaurus databases to add to my TexStudio environment. Can you please direct me where can I find such thing? Which dictionary should I take from OpenOffice or LibreOffice so I will be able to ctrl+shift+F8 on words and see its synonymous.
The latest one I was able to find was from LibreOffice, last updated Jan 2017. It does say that it is a dictionary, but I find it works fine as a thesaurus as well.
For example, the word
happy gives this:
If you would like to know how to make the thesaurus work in TeXstudio, see my other answer here. (Your question only asked about where to obtain such a thesaurus file).