I'm not a native speaker, but I remembered the word "easen" from some previous experience, and wanted to use that. I found an entry in Wiktionary on that word with many examples (though mostly technical ones), but I could not find it in any other dictionary (also any note that it was considered "incorrect").
I also checked Google ngram, and this word is indeed used incomparably less often than its synonym "ease".
My question is: does this word exist? Is it correct in any branch of English? Does it sound correct to native speakers? Why is its usage so nonfrequent? (BTW, "nonfrequent" is also present in Wiktionary, but I couldn't find it in other dictionaries).
I would add some usage notes to Wiktionary, so references would be appreciated.