Ralimar

It likely intentionally has multiple meanings. I suspect one possible meaning is an un-splintering of the Honor shard. Which would be a big deal both for the SA and the Cosmere as a whole. That may be the event that gets us to a post-Book 5 Roshar equilibrium that ends the first arc of books. We see that Tavanast had some long game that he was playing, and the shard ends up falling into the hands of Dalinar or Kaladin, or something along those lines.