estrogen antagonist estrogen • estrogenic · · · Info · Definitions · Synonyms · Characters · · estrogen antagonist · · Text Common · · Latin · · Scripts 19 · · Length 7 · · Syllables Definitions · · · (noun) an antagonist for estrogen that is used in the treatment of breast cancer. Synonyms: estrogen antagonist, tamoxifen. · · Noun Definition 1 Synonyms · · · tamoxifen · · Synonym 1 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 g latin small letter g U+0067 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074