Complex sentence: Homosexuality remained unseen and taboo concept in society, and the word "homosexuality" was not coined until 1868 by German-Hungarian Karoly Maria Kertbeny (who advocated decriminalization).
Split into simpler sentences: Homosexuality remained unseen and taboo concept in society. In fact, the word "homosexuality" was not coined as a word till 1868 by German-Hungarian Karoly Maria Kertbeny (who advocated decriminalization).