asymmetry

noun2

1. •
   An absence of symmetry or proportion between the parts of a thing, or a distinction that produces such a lack of symmetry.

   • Despite the generally symmetrical appearance of the two hemispheres, however, a number of biological asymmetries have been documented during the last hundred years. — 1993
2. •
   The lack of a common measure between two objects or quantities; incommensurability.