A biologic response to exposure to multiple substances that is less than would be expected if the known effects of the individual substances were added together [compare with additive effect and synergistic effect]
Agency for Toxic Substances and Disease Registry, Centers for Disease Control and Prevention, Glossary of Terms, Atlanta, GA, USA 2009. http://www.atsdr.cdc.gov/glossary.html, (Tox - Amer) {788}