Oneiromancy (yet another word I will struggle to pronounce, let alone spell) is divination through dreams. To put it another way, people who practice oneiromancy are trying to reveal the future (or the unknown) through dreams.
This is, typically, one of those fields without any form of scientific validity. It’s nonetheless something that can feel sort of… haunting. I’m pretty sure a lot of us have dreamed of events that then manifest themselves in some form, even if the details aren’t necessarily the same. Of course, a lot of this is more to do with coincidence than anything else. If you think a lot about an upcoming flight, meal, event or interview, the chances are you’ll dream about it, and depending on how vivid your imagination is, that dream might end up feeling very real. It may seem so real, and so similar to how events play out, that you might even briefly think you’ve seen the future, but sometimes, a coincidence is merely a coincidence.