Well, if that particular phrase is poisoned, I guess I could just say "Hobbit" instead, which is owned as a trademark IIRC by the Tolkien estate and they're very litigious about it.
You can't say "Hobbit" in your own stories. But you can say "Halfling", and that's how people tend to get around that problem. Blonde Thor is Disney/Marvel (Historical Thor was a redhead IIRC, so Blonde Thor is Disney/Marvel Trademark), etc. etc. Plenty of restrictions on Free Speech in practice.
You can't use it to market your stories or other products, and there's some manners of use innthr body of a book that might run some risk of liability for dilution or tarnishment, but...
Of course you can. You can write about hobbits, make youtube videos discussing them, whatever. There's a lot of fanfic on hobbits out there. You can make fun of hobbits.
If you want to use copyrighted characters and it's not fair use, then no.
You can't say "Hobbit" in your own stories. But you can say "Halfling", and that's how people tend to get around that problem. Blonde Thor is Disney/Marvel (Historical Thor was a redhead IIRC, so Blonde Thor is Disney/Marvel Trademark), etc. etc. Plenty of restrictions on Free Speech in practice.