Booru
It's Japanese slang for Hentai sites that serves pictures in board form, but you have to sign in to get the real subject or you will only get mainstream pics.
Kusubooru is my favorite out of all boorus, because it mainly serves my fetish.
booru
short for "danbooru-style board"; a type of imageboard that relies on a non-hierarchical structure in which users are allowed to post content, add tags, and write comments
E621 is a booru for furries.