noun. A nonsteroidal synthetic drug, C₁₈H₂₀O₂, having estrogenic properties and used in the treatment of advanced prostate cancer. Before 1971 it was prescribed to prevent miscarriage and to treat menstrual disorders but was found to cause vaginal cancer and other reproductive abnormalities in the daughters of pregnant women so treated.

noun. An orally-active synthetic nonsteroidal oestrogen, first synthesized in 1938 and withdrawn in the 1970s on being identified as a teratogen.

noun. a potent estrogen used in medicine and in feed for livestock and poultry

"In 1971, yet another such study identified an even more unusual carcinogen, a synthetic hormonal medicine called diethylstilbestrol DES."

estrogen  oestrogen  

DES