ONAN ō’ nən (אﯴנָנ׃֙, strong). The second son born to Judah and a Canaanitess named Shua. After the death of his older brother Er, whom the Lord slew for his wickedness, Onan, commanded by his father Judah to enter into a levirate marriage with his brother’s wife Tamar, failed to consummate the union. For this sin the Lord punished him with death (Gen 38:1-11). Onan’s name is mentioned also in Genesis 46:12; Numbers 26:19; 1 Chronicles 2:3.