Q: In Jen Beagin’s 2023 novel Big Swiss, Flavia asks Om, her sex therapist, whether “adult” and “adultery” are related. He says they aren’t. Huh? Could that be right?
A: Yes. Both English words ultimately come from different classical Latin sources: “adult” from adultus (full-grown, mature), and “adultery” from adulterare (to commit adultery, debase, counterfeit, or corrupt).
The first of these terms to appear in English, “adultery,” was recorded in the early 14th century, according to the Oxford English Dictionary. The earliest OED citation is from a statute, dated sometime before 1325, in A Middle English Statute-Book (2011), edited by Claire Fennell:
“Ant te womman, ȝif heo mide hire oune wille forsok hire hosebonde, ant tuuelde in hire aduoterie, a sal lusen aremanaund accion to purchasen hire dowere of þe tenement of þe foreseide man þat was hire lord.”
(“And the woman, if she of her own free will forsook her husband and lived in adultery, she shall lose forever the right of action to claim her dower [a widow’s share of her husband’s estate] from the holding of the aforementioned man who was her lord.”)
The earliest Oxford citation for the adjective “adult” is from a treatise on how to train statesmen: “Soche persons, beinge nowe adulte, that is to saye, passed theyr childehode” (The Boke Named the Gouernour, 1531, by the English scholar and diplomat Thomas Elyot).
The noun “adult” appeared a century later. The OED example is a from a treatise critical of Anabaptism, the doctrine that baptism should be administered only to believing adults.
In this passage from Anabaptism Routed (1655), John Reading argues that being baptized as a baby provides a stronger Christian foundation than later baptism:
“In the adult, coming to the knowledge of God’s covenant in Christ, and of his own feeling in infancy, it must make him more confident of his implantation into Christ, then if he knew that he never had been baptized.”
To get back to your question, no, “adult” and “adultery” are not related, but only the former can commit the latter.
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