From 2015-2017, Wordset.org provided a public interface for anyone to help collaborate on the world's first open source, collaborative dictionary.
However, due to... well, cough lack of interest... we decided to shutdown the project.
Here we are providing the final, most up-to-date release of the Wordset Dictionary. I'll answer some questions inline about the data and what you can do about it.
https://github.com/wordset/wordset-dictionary
Format is JSON and is split by first letter. Data is here: https://github.com/wordset/wordset-dictionary/tree/master/data