Definition of "antiestrogenic"

Tamoxifen, a nonsteroidal antiestrogenic agent, is used widely as adjunctive therapy for women with breast cancer.

2015, Alka Jindal et al., “Endometrial evaluation by ultrasonography, hysteroscopy and histopathology in cases of breast carcinoma on Tamoxifen therapy”, in Journal of Mid-Life Health‎, volume 6