Biblical Hebrew name meaning 'strength' or 'vigor,' borne by a son of Judah in Genesis.
Onan is a biblical name of Hebrew origin, appearing in the Book of Genesis as the second son of Judah and a Canaanite woman named Shua. The Hebrew root is most commonly linked to on, meaning strength or vigor, a perfectly honorable meaning in the tradition of Old Testament names that announced a child's hoped-for qualities. Judah's firstborn sons bore names of similar construction, and Onan would have entered the world with no particular shadow attached to the name itself.
What followed in the text transformed the name irrevocably. The story in Genesis 38 — in which Onan refuses to fulfill his levirate duty to his deceased brother's wife Tamar and is struck dead by God — gave rise centuries later to the term onanism, coined in a 1716 anonymous treatise that misread the narrative as a condemnation of masturbation rather than, as most modern scholars argue, a violation of the levirate law. The word became clinical, satirical, and eventually entered ordinary language.
The name itself carries that burden forward, making it effectively unusable as a given name in most modern Western contexts despite its ancient and etymologically innocent origins. In the history of names, Onan stands as an unusual case study: a name whose meaning (strength) is entirely positive, whose bearer committed an offense against social law rather than natural law, and yet whose legacy was hijacked by a centuries-long misreading to produce one of the most stigmatized lexical descendants in the English language. Scholars of biblical onomastics and historians of sexuality both find the name instructive — it is a reminder of how profoundly the cultural afterlives of names can diverge from their origins.