[ ih-pis-tuh-sis ]
/ ɪˈpɪs tə sɪs /
Save This Word!

noun, plural e·pis·ta·ses [ih-pis-tuh-seez]. /ɪˈpɪs təˌsiz/.

Genetics. a form of interaction between nonallelic genes in which one combination of such genes has a dominant effect over other combinations.
  1. the stoppage of a secretion or discharge.
  2. a scum that forms on a urine specimen upon standing.



In effect, this quiz will prove whether or not you have the skills to know the difference between “affect” and “effect.”
Question 1 of 7
The rainy weather could not ________ my elated spirits on my graduation day.

Origin of epistasis

First recorded in 1915–20, epistasis is from the Greek word epístasis stopping, stoppage. See epi-, stasis
ep·i·stat·ic [ep-uh-stat-ik], /ˌɛp əˈstæt ɪk/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for epistasis

/ (ɪˈpɪstəsɪs) /


obsolete scum on the surface of a liquid, esp on an old specimen of urine
med the arrest or checking of a bodily discharge, esp bleeding
Also called: hypostasis genetics the suppression by a gene of the effect of another gene that is not its allele
epistatic (ˌɛpɪˈstætɪk), adjective
C19: from Greek: a stopping, from ephistanai to stop, from epi- + histanai to put
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for epistasis

[ ĭ-pĭstə-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.
ep′i•static (ĕp′ĭ-stătĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Learn A New Word Right Now!