Rez (in Second Life) means to create or to make an object appear. If something were to appear out of nowhere, someone should say it "Rezzed in". Reresolution, or just simply, rerez, is when a program who was derezzed, "comes back to life", or resurrected. The term was inspired by the classic science-fiction movie Tron.
In Second Life, two friends teleport into a new location - "Oh, this place is beautiful!", "Can't see yet, I'm still rezzing."