The Dictionary of Obscure Sorrows “is a compendium of invented words written by John Koenig. Each original definition aims to fill a hole in the language—to give a name to emotions we all might experience but don’t yet have a word for.”
For example, kenopsia is “the eerie, forlorn atmosphere of a place that’s usually bustling with people but is now abandoned and quiet—a school hallway in the evening, an unlit office on a weekend, vacant fairgrounds—an emotional afterimage that makes it seem not just empty but hyper-empty, with a total population in the negative, who are so conspicuously absent they glow like neon signs.”
Apparently there are or were plans for a book version from Simon & Schuster, though the announcement of that came out a couple years ago and the book doesn’t seem to be published yet. And there’s a Facebook page.