said. Gynecomastia , pronounced /ˌɡaɪnɨkɵˈmæstiə/ , is the abnormal development of large mammary glands in males resulting in breast enlargement. The term comes from the Greek γυνή gyné (stem gynaik- ) meaning "woman" and μαστός mastós meaning "breast". The condition can occur physiologically in neonates (due to female hormones from the