WordNet (r) 3.0 (2006):

epistasis
    n 1: the suppression of a gene by the effect of an unrelated
         gene [syn: hypostasis, epistasis]

The Free On-line Dictionary of Computing (19 January 2023):

epistasis

    In genetics, espistasis is the interaction between
   the effects (phenotype) of different genes.  E.g. a gene for
   baldness may hide a gene for red hair.  The concept can also
   describe unexpected interaction between software systems
   that should be independent.  E.g. one function wrongly adds
   one to its output which is fed to another function that
   wrongly subtracts one from its input, resulting in the correct
   output from the combination.  The two bugs can remain hidden
   until one of them is fixed.


(https://cryptogenomicon.org/2014/10/13/cryptic-genetic-variation-in-software-hunting-a-buffered-41-year-old-bug/).

   (2019-09-01)