Reddit has subreddits. What does Lemmy go with?
My personal vote is for lemmings!
Edit: I am personally leaning towards Sublemmy now. It retains the context of being a forum under the general sphere of Lemmy and the connection to Reddit lets people know immediately what Lemmy is about. Thanks to @BurningnnTree@lemmy.one for the comment!
OK, so a group of lemmings is called a “slice”. That kinda has a nice ring to it, “I joined this slice of the fediverse” or “the mods on this slice are all terrible!!!”