tamoxifen Syllabification: (ta·mox·i·fen)Pronunciation: /təˈmäksəfən/Definition of tamoxifen noun Medicine a synthetic drug used to treat breast cancer and infertility in women. It acts as an estrogen 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 British & World English dictionary
