A recent news article prompted me to research the use of jack as a catch-all term: Apparently, a pair of pot smugglers ignored the sensible admonition “Don’t get high on your own supply” and, in a state of THC-fueled paranoia, called 911 to complain that while transporting their precious cargo, they were being harassed by undercover police officers in nearby vehicles. The caller referred to the alleged persecutors—probably just fellow motorists perturbed by the unsteady hand of the man at the wheel—as “jackwagons.”
All usages of jack in English, it turns out, derive from the proper name Jack, a variant of the common names John (from English, but ultimately derived from the Hebrew name Yochanan, also the source of the name Jonathan) and Jacques (the latter of which, from France, is the origin of the word jacket). The ubiquity of these names in medieval England resulted in its use as a general term of address for the common man. (In Middle English, it was spelled various ways with an e at the end and pronounced “Jackie,” hence the diminutive form of the nickname.)
The Scots equivalent, Jock, was the origin of the word jockey, used to describe someone who rides or drives a horse in a race or, by extension, operates a vehicle or a tool (as in “disk jockey,” the origin of the entertainment term DJ, also spelled deejay). To jockey, on the analogy of a jockey’s riding strategy, is to maneuver or negotiate for advantage.
From the usage of Jack as a generic name stems such terms as lumberjack for a worker who cuts trees down and steeplejack for someone specializing in working on tall structures, jack-of-all-trades, referring to a person who is skilled at multiple types of jobs or tasks, and jack-o’-lantern (“jack-of-the-lantern,” originally synonymous with will-o’-the-wisp) and jack-in-the-box, the name for a toy and a carved pumpkin lit from within respectively, as well as “Jack Frost” as a personification of wintry cold and “Jack the Ripper” as a nickname for a notorious serial killer in Victorian London. (Jack-in-the-box was originally slang for a con man who switched out a full box for an empty one, and it acquired numerous other senses, too.)
The name also became associated with sailors in the designation “Jack Tar,” thanks to the fact that men of the sea generally had a scent of tar about them. Fictional characters given the Everyman appellation in tales and nursery rhymes include the heroes in “Jack and the Beanstalk” and “Jack the Giant Killer” and personages in “Jack Sprat” and “Jack and Jill.”
Jack was also applied to the lowest-ranking face cards in a deck of playing cards (which is the origin of jackpot, meaning “a prize,” and hence jack, a slang term for money) and to various small objects, including flags (as in “Union Jack”) and the game of jacks and its playing pieces. The sense of “small” is also responsible for the retort “You don’t know jack shit” (or just “jack”).
It also appears in the name of animals and plants, including the jackass, or male donkey, the jackrabbit (a hare named for its long ears, suggestive of a donkey’s), and the jackdaw, a relative of the crow, plus the jack oak and jack pine trees, as well as the jack-in-the-pulpit plant. Jackanapes, from the nickname given to an upstart English nobleman, derives from “Jack of Naples,” a contemporary slang term for a monkey that came to refer to an impudent person. The cheese variety Monterey Jack was named after its first commercial producer, David Jack, who lived near Monterey, California.
The noun jack, referring to various mechanisms, including a device for hoisting or raising a heavy object, and the verb form jack and the verb phrase “jack up” derive from the fact that the machines did the work of a common laborer. Jackhammer and jackknife, as well as the term bootjack, for a device used for removing boots, stem from this usage as well.
(However, jackboot, referring both to a boot worn by cavalry soldiers and a later marching boot worn by German and Soviet military personnel—hence the word’s subsequent association with totalitarian oppression, although jackboots have been worn by soldiers of democratic nations as well—is unrelated: The cavalry jackboot was originally fortified with chain mail, and an Old French word for that material is jaque.)
So, how did we get to the insult jackwagon, popularized in a television commercial featuring actor and former drill sergeant R. Lee Ermey? As a less offensive alternative to jackass as a derogatory label, it may derive from a nickname for the chuck wagon (chuck comes from a slang word for food), a vehicle carrying cooking implements and supplies for a cattle drive or a wagon train, or for any of one of several other types of wagons that might bring up the rear of a procession of other vehicles. The seemingly lowly status of the trailing wagon, literally left in the dust of what came before it, presumably came to be associated with a person of low character or intelligence.