[tuh-rat-uh-juh n, -jen, ter-uh-tuh-]

noun Biology.

a drug or other substance capable of interfering with the development of a fetus, causing birth defects.

Origin of teratogen

First recorded in 1900–05; terato- + -gen
Related formste·rat·o·gen·ic, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for teratogen



any substance, organism, or process that causes malformations in a fetus. Teratogens include certain drugs (such as thalidomide), infections (such as German measles), and ionizing radiation
Derived Formsteratogenic, adjectiveteratogenicist, nounteratogenicity, noun
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

Word Origin and History for teratogen

1959, from comb. form of Greek teras (genitive teratos) "marvel, monster" + -gen.

Online Etymology Dictionary, © 2010 Douglas Harper

teratogen in Medicine


[tə-rătə-jən, tĕrə-tə-]


An agent, such as a virus, a drug, or radiation, that can cause malformations or functional damage to an embryo or a fetus.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

teratogen in Science


[tə-rătə-jən, tĕrə-tə-]

An agent, such as a virus, a drug, or radiation, that can cause malformations in an embryo or fetus.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.