Memne theo is a Greek phrase that was the core of a lot of Byzantine monastic thought for a while. It means literally, the "memory of God." However (at least according to my source, Mary J Carruthers --not speaking a lick of Greek myself, I'm not in any place to argue with her) memne means much more than memory as we know it in this case. It is a sort of semi-religious experience, the deep knowledge of something.
I've been thinking about how to adapt memne theo into something that can be used in the 10th Age. My current notion is that those priests who have a divine connection and can make use of sacred magic (a small minority of all priests) are accessing something similar to the monastic idea of memne theo. Thus, the actual term for preparing priestly magic can be something like "divine memory," or the "memory of the gods."