atavic

[Fr. atavique.] [ATAVISM.] Pertaining to or derived from a remote ancestor. ăť-a-vism, s. [Lat. atavus = (1) the father of the great-great-grandfather or great-great grandmother; (2) an ancestor, forefather; avus (1) a grandfather, (2) an old man.] 1. Biology : The reversion of a descendant to some peculiarity of a more or le remote ancestor. 2. Med. The recurrence of a disease from which a more or le remote ancestor suffered, but which has not appeared in the intermediate generations.