ONAN. – Second-born son of Judah, son of the patriarch Jacob, by his Canaanite wife, Sue.
Since his brother Her had died without offspring, following his father’s advice and in accordance marriage (v.), practiced even before the Mosaic legislation, he married his widow Thamar. But, unwilling that the offspring to be born should be attributed to his deceased brother, as levirate marriage required, he united with his wife in such a way as to prevent conception. As punishment for this ignoble crime, he was put to death by the Lord (Gen. 38:2–4; 46:12). The sin against nature directed toward preventing offspring takes its name from him and is called “onanism.”