I found out what most of the words mean, but I was stuck on how to make sense of it. I emailed my husband because he knows a lot about the Latin language. His response was this:
"The correct literation of the sentance is 'Literatim Et Verbatim Gravoria Manent'; translated, it means "Literally and after the wording still heavier things remain". Gravoria I found in a latin dictionary meant 'to oppress, to make suffer. Manent means, 'they remain'.
Embarassed by my first answer now - usually research things much better than that! Got it off a fan site for The Exorcist - The Beginning, which uses it in the script. Darn tint'net