Yes! I am now home! I will put the definition in a spoiler box, just to be safe! Ahem! The Void is...
Then it directs you to see the "flame and the void" which is, possible spoiler...
Then it says to see our last related definition, Oneness, which is as follows. Possible spoilers.
So these are the definitions. This is from the WOT companion book, which I highly recommend. It's great for a reread as it has maps, easy to look up and more detailed definitions. I would looooove one for Stormlight as it will be a long series and having one book with maps and definitions and small backstories on topics such as Aimia would be amazing. But I'll just settle for more stories of my loves Kaladin and Renarin right now. It's good enough for me.
P.s. don't get the companion book if you are reading through the series for the first time. If you thought New Spring would spoil things, well let me tell you this book is even worse when it comes to spoilers!