There is currently a phenom sweeping the writing world. An author (who won’t be named here because I refuse to grant them any publicity) has not only gone all out (involving lawyers) to claim sole and exclusive use to a word (which I also will not name) in his or her books as it’s part of a series title, but also has gone out after any authors who have used the word *prior* to the series publication.
Sounds to me like someone put Fleet in their Wheaties.
First off, you can’t copyright a word in common use, unless it is a specific brand or product name (see above). And these are called trademarks. There are rules about that.
Book titles aren’t copywritten.
Nor can you go after people who used “your word” in published materials before you showed up, and insist that they pull those works and remove “your word” or you’ll sue. Oh, and a formal apology is expected, or the deal’s off.
This is professional bullying of the worst kind. As I’m sure this individual is slowly realizing, the doors to the hallowed halls of publishing are slamming shut in their face.