tamoxifenPronunciation: /təˈmɒksɪfɛn/Definition of tamoxifen noun [mass noun] Medicine a synthetic drug used to treat breast cancer and infertility in women. It acts as an oestrogen antagonist. Origin: 1970s: an arbitrary formation based on trans-, amine, oxy-2, phenol, elements of the drug's chemical nametamoxifen in other Oxford dictionaries Definition of tamoxifen in the US English dictionary
