Onan

Onan (אונן "Strong", Standard Hebrew Onan, Tiberian Hebrew ʾÔnān) is a person described in the Bible (book of Genesis). He was the second son of Judah. His name is the origin for the sexual term onanism (synonym of masturbation), which is nowadays considered to be based on a misinterpretation.

After his older brother Er died Onan was to marry Er's widow Tamar (this was the practice of levirate marriage). According to the Bible, whenever he had sexual intercourse with his brother's wife he spilt his semen upon the ground (Genesis 38:7-9); the Bible says that he did this because (under the custom of levirate marriage) the child would not be considered his, but his late brother's. In response to this transgression, God killed Onan.

Ancient Jewish and Christian authors understood the activities of God in this story as a condemnation of masturbation, and this is still the prevalent view in some religious circles. Most modern Biblical scholars, however, say that Onan's sin was to violate the rules of levirate marriage, the Biblical law which states that a childless widow marry her late husband's brother. It is now generally agreed that the passage refers to coitus interruptus rather than masturbation.