To be continually in the act of hating other people's ideas and lifestyles, based solely on your poor outlook on life, and not on actual, concrete facts.
A Fandom that is dedicated to hating a work, idea, community or author, instead of loving it.
Of course, to have some form of credibility, it's best to have actually read/watched/played/listened/joined/followed to some of the hated work, but some people usually hate without having any knowledge or something parroted to them by another hater.
If you hate the fandom of a loved work, you part of a Hatedom.
If you hate the fans of a fandom, that makes you a Fan Hater.
A Fan Hater does not have to be part of a Hatedom.
Anti-Fans of a work are likely to view its fandom as a Fan Dumb.
Fans of a work are likely to view its Hatedom as a Hate Dumb.
hate room is a room devoted to someone you hate. It might include such things as a voodoo doll of the person you hate or bad things written about the person on the wall.