According to the website: "The Dictionary of Obscure Sorrows is a compendium of new words for emotions. Its mission is to shine a light on the fundamental strangeness of being a human being—all the aches, demons, vibes, joys, and urges that are humming in the background of everyday life."
This definition sounded very much like the sort of thing which would be in that book. So I took a look and it does seem to be: https://www.thedictionaryofobscuresorrows.com/word/midding
