Onan is a figure from the Bible, specifically mentioned in the Book of Genesis. He was the second son of Judah and Shua, and his story is often associated with the concept of "onanism," which refers to the act of masturbation. Onan was instructed to marry his deceased brother's wife, Tamar, to produce offspring in his brother's name. However, he disobeyed this command. In his disobedience, Onan practiced coitus interruptus, which led to his punishment by God. This act has been interpreted in various ways throughout history, influencing discussions on sexuality and moral behavior in different cultures and religions.