APA Dictionary of Psychology

n. a synthetic, nonsteroidal compound with the activity of estrogen. It was at one time widely prescribed to pregnant women to prevent miscarriages or premature deliveries, but such use was discontinued in the early 1970s due to the health risks associated with DES, including increased risk of reproductive abnormalities and cancer in female offspring. It is still used clinically to treat selected cases of breast cancer or prostate cancer, but this is very rare. See also endocrine disruptor.