In case it helps anyone, I just finished putting together a repository of a word list of synonyms and antonyms parsed from a Project Gutenberg public domain book: A Complete Dictionary of Synonyms and Antonyms by Samuel Fallows, 1898. You can find the repository and more details at https://github.com/verachell/English-word-lists-synonyms-antonyms.
I wanted such a list under a permissive no-attribution licence for use in my NaNoGenMo project, so I decided to create one by parsing the book of Samuel Fallows. This was a quickly-put-together repository that I did at the start of NaNoGenMo 2020 and is licensed under the Unlicense, so no attribution is needed. I will update the repository if I find problems as I use it. Please also feel free to let me know if you discover any problems if you use it.
I'm updating to add in these additional word lists that I just finished putting together. No attribution is needed; they are licensed under the Unlicense.
Glad to see the AIGC emerge on the Internet by the help of Artificial Intelligence.
I wish to see more amazing & exciting & inspiring tools for creators in the world to generate and more easily create high-quality content.