an·​ti·​hor·​mone ˌan-tē-ˈhȯr-ˌmōn How to pronounce antihormone (audio)
: a substance (such as tamoxifen) that blocks the action or inhibits the production of a hormone

Word History

First Known Use

1908, in the meaning defined above

Time Traveler
The first known use of antihormone was in 1908

Dictionary Entries Near antihormone

Cite this Entry

“Antihormone.” Dictionary, Merriam-Webster, Accessed 24 Sep. 2023.

Medical Definition


1 of 2 noun
: a substance (as tamoxifen) that blocks the action or inhibits the production of a hormone
… a group of naturally occurring plant chemicals that weakly mimic the effects of estrogen hormones in some parts of the body while acting like antihormones in others.Christine Gorman, Time
dated : a fraction of blood globulin that is capable of rendering ineffective a protein-containing heterologous hormone when the latter is administered over a period of time and that is now generally considered to be a true antibody formed in response to the presence of foreign protein
Although subsequent work disproved the idea that antihormones played any physiological role in the control of endocrine organs, these experiments excited wide interest at the time and raised the question of species-specificity of protein hormones in therapeutic procedures.R. L. Noble, The Canadian Medical Association Journal


2 of 2 adjective
variants also anti-hormone
: of, relating to, or using antihormones : antihormonal
antihormone treatment
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