[avidiax]

If you like this, you would probably enjoy Princeton Wordnet. They have unfortunately stopped developing it.

You can still browse it a bit online with some 3rd party sites: https://en-word.net/

[jaen]

The page literally credits "Open English Wordnet" (based on it) in the sidebar :)

(the link is broken though, it should be https://github.com/globalwordnet/english-wordnet)

[wyattsell]

fixed, thanks for pointing that out.