A Catalyst is an item a player must wield to cast sorcery magics.For more information, see: Catalysts
This should really just redirect to the Catalysts page. I actually made an account just to do that but it turns out normal users can't I guess. The best I could do is at least link to it and correct the spelling. I'm not entirely sure how I always end up here instead of the Catalysts page, but it was annoying enough I tried to fix it.