This is a follow-up to Add a Wiki page for the "compounds" tag, or replace it with another tag; when that task has been completed, and no question is tagged with "compounds", we would probably need to blacklist the word to avoid it gets used as tag.
Hold on a sec. When I hear "compounds", I don't think of compound sentences. I think of compound words.
So, while having both compound-words and compound-sentences — as proposed in that other question — might make sense, I don't see how that would mean that we must throw compounds away. If anything, it could be made a synonym of compound-words (though I would probably favor the exact opposite thing, i.e. making compound-words a synonym of compounds).
Blacklisting is there for really awful, utterly useless tags people resort to when they can't think of anything remotely meaningful. Blacklisting is not for well-established linguistic terms that people have all the right in the world to use. There's a reason why mods cannot blacklist, only devs can. Quoting Jeff, "it's something the dev team has to enter because it's so dangerous to get wrong. We work with the existing site moderators to determine what's bad enough to be blacklisted. It has to be quite bad."