Why do we call them headphone “jacks”?

Apple turned many heads this week when it announced it’s scrapping the headphone jack in the iPhone 7. The jack, that little socket you plug your headphones into and sometimes the word for the plug itself, has had a good run: It’s a durable bit of technology dating back to the 19th century. But why we call it a jack is much, much older.

A jack of all trades

Since at least the late 1300s, jack has been naming all sorts of mechanical devices. One prominent contrivance is the Jack of the clock, simply called Jack at the end of 1400s. This was a little, mechanized man who strikes the bells on old clocks. Other early jacks include a turner of a roasting spit, a wooden frame for sawing, and various rollers and winches. The Oxford English Dictionary (OED) finds all these uses in the 1580s.

Many such jack technologies proliferated in the 17th, 18th, and 19th centuries, like the lifting-jack, which we still use, essentially, in changing a flat tire today. This is why we jack up, or “raise,” prices. Jack was first used of telephony, at least according to the OED’s account, in 1891, referring to that special electrical socket Apple is obsolescing. Plugging this socket is a jack plug, or now just jack, attested by 1931. Headphone actually predates both of these, appearing by 1882.

Early on, many of these jacks replaced the work of a man. Think of Jack of the clock, whose automatized timekeeping saved the services of some clocktower attendant in addition to providing an impressive, ornamental display of technological progress. During this period of history, Jack was a widespread nickname for any old regular guy. (We do this today with our Average Joe, Dear John, and even hip-hop’s New Jack.) And so the various tools and technologies took the name of the man they stood in for: Jack.

Jacks are truly an everyman in the English language. We see them in jackass, jack of all trades, jack-o’-lantern, lumberjack, Union Jack, you don’t know jack, and jackpot, whose jack, as I previously discussed, answers to the card suit.

Jack today, gone tomorrow

Now, in English, Jack has long been a pet form of the name John, historically one of the most common first names for men. We have evidence for it in the 1300s. Some think this Jack was a homegrown nickname, but most etymologists think Jack actually comes from the French name Jacques, also used as a familiar, often contemptuous name for a common man or peasant.

Jacques is ultimately a French form of name Jacob: Latin’s Iacōbus yields Jacques (and James), the Greek Ἰάκωβος (Iakobos) yields Iacōbus, and the Hebrew יַעֲקֹב (Ya’akōbh, among other renderings) supplies all of the above.

Scholars have given a few interpretations to the meaning of Jacob. One is that it comes from the Hebrew word for “heel” (ʿaqeb, approximately) also carrying a sense of “to follow.” For this, they point to the biblical Jacob, younger twin to Esau. The Book of Genesis describes his birth: “And after that came his brother out, and his hand took hold on Esau’s heel; and his name was called Jacob.” 

But in a later passage, Jacob takes on a more metaphorical meaning. When Jacob cheats his brother out of his birthright, Esau cries: “Is not he rightly named Jacob? for he hath supplanted me these two times: he took away my birthright; and, behold, now he hath taken away my blessing.” Here, Jacob means “supplant.”

Jacob supplanted Esau. Jack supplanted Jacob. The mechanical jack supplanted Jack the workman. And Apple’s AirPods are supplanting the headphone jack. It’s as if the technology was etymologically bound to be replaced.