The word Apos refers to the extreme Ana side of a 4-dimensional object or space. It is sometimes incorrectly referred to as the "top", in order to communicate the concept to the uninitiated. The opposite term is Zakos.
The words Apos and Zakos were created by Oren Otter for the purpose of having clearly defined terms when discussing 4-dimensional space with aficionados of the topic. They have since become accepted as standard terms.
In the multiverse, the most magical realm is at the apos of the multiverse, where magic is so thick that life cannot exist. Magic flows from this realm at the apos toward the zakos.