A circle multiverse is a type of 4+1-dimensional multiverse in which multiple universes are arranged in a ring, with each universe being adjacent to exactly two other universes (one in each direction). Traveling far enough in a circle multiverse will eventually take the traveler back to their origin universe. The rings shape does not need to be regular and its curvature does not need to be regular. It can even have straight segments or segments with negative curvature, as long as it comes back into itself at some point. Its shape can be anything but its topology must be that of a circle.
A similar type of multiverse, but without any curvature, is a line multiverse.