Avoid the misspelling/mispronunciation diethylstilbesterol. A synthetic nonsteroidal estrogenic compound. Sometimes used as a postcoital antipregnancy agent to prevent implantation of the fertilized ovum. The first demonstrated transplacental carcinogen responsible for a delayed clear cell vaginal carcinoma in female offspring of mothers who took the drug during pregnancy when the drug was erroneously thought to prevent threatened abortion. SYN: stilbestrol.
