Today's Word of the Day means...
epistasis e·pis·ta·sis (ĭ-pĭs'tə-sĭs)
n. pl. e·pis·ta·ses (-sēz')
A film that forms over the surface of a urine specimen.
An interaction between nonallelic genes, especially an interaction in which one gene suppresses the expression of another.
The suppression of a bodily discharge or secretion.