Materteral: 1. Literally, relating to a maternal aunt.
2. Figuratively, suggestive of an aunt on either side of the family. 3 In medical genetics, pertaining to an aunt. An materteral relationship is the genetic relationship between aunts and their nieces and nephews. Materteral is synonymous with materterine. From the Latin matertera meaning maternal aunt, from mater meaning mother. The feminine counterpart of avuncular (like an uncle).