noun \-ˈhr-ˌmōn\

Definition of ANTIHORMONE

: 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
: a substance (as tamoxifen) that blocks the action or inhibits the production of a hormone

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