Universions

From The Encyclopaedia Expurgatia

The vernacular oversimplification of the minute differences betwixt otherwise similar universes within the multiverse, and subsequent alternate realities.

Universions are, simply, differing types of normalcy.

For example: Universe 97D has a Milky Way Galaxy whose System of Sol contains a planet called Earth upon which deinosaurs once lived; those deinosaurs disappeared as a large asteroid smashed into the Yucatan.

In another universion, in Universe 97T, the disappearance of the deinosaurs was attributed to a comet which passed too close to the planet.

That comet irradiated the planet and caused mass extinction, both directly and indirectly.

Unlike 97D's asteroid, 97T's comet survived the extinction, and returned to kill again at the end of the twentieth century.