On a recent trip to Chicago, I kept noticing a certain two-letter word. It greeted me on the way to baggage claim at Midway Airport.

"ChicaGO relax."

It was on the shuttle van that took me to my hotel.

GO Airport Express.

And it loomed over me from the side of a State Street building.

" Instant GO," a Nike ad slogan.

Of course, GO-mania isn’t an only-in-Chicago phenomenon, despite the convenient final syllable of that city's name. Walking to my gate at Oakland International Airport, for example, I encountered "Grab & Go" airport-meal kiosks, a fixture of the austerity era of air travel. A bike-share network all over the Bay Area is called Ford GoBike. The premium cable channel HBO offers a streaming-video-on-demand service called HBO GO. Swimmers, cyclists, and climbers strap on GoPro cameras to shoot action footage. The new virtual-reality headset from an industry pioneer: Oculus Go. And remember the gaming phenomenon of the summer of 2016? That's right: Pokémon GO. Two years later it's still, well, going strong.

As a shorthand suffix meaning "mobility, especially of the electronic-device category" go is relatively new, and its ubiquity feels sudden. But go has been with us as a verb since the dawn of English, and as a noun – "the action or fact of going" – since the 17th century. Later, it found new life as an interjection such as "Go, team!" (first seen in print, according to the OED, in 1831) and an adjective (in the 1930s and 1940s, a "go man" or "go girl" was modern and fashionable; beginning in the early years of manned space flight, an engine or system has been "go" if it's ready for implementation).

Go can mean to live or to die; in past centuries it also meant to be pregnant (for example, "The female goes two months, and then brings forth two young ones"). It can mean to travel, to occur, or to elapse, to function, or to have authority ("What I say goes!"). It has meant "to pay a visit to the toilet" (as the OED primly puts it) since Old English.

Charmin toilet paper introduced its "Enjoy the Go" slogan in 2009. More on the ad campaign here.

Go is nothing if not flexible; the OED gives 48 primary definitions just for the verb, and scores of sub-definitions. Go pairs willingly with almost any preposition: a gun can go off (first citation: 1560), as can an alarm (1810) and food (1913). There are 26 separate definitions for to go down, among them "to put a baby to sleep" (first documented in 1922, in an American newspaper) and "to be sent to prison" (also U.S., 1906). Websites go up (1995); when businesses fail they go under (1882) or go south (possibly adapted from a Native American euphemism for death) A couple may go out ("to date," first documented in this sense in 1907), and if they get along they may, quaintly, go steady (first used by Edith Wharton in The House of Mirth, 1905) or go together (which meant "copulate" in the 1300s and the milder "be in a romantic relationship with" since about 1871). If not, each person may choose to go it alone (documented as an idiom in 1842).

Go lends itself to hyphenated compounds. A go-between has meant "a mediator" since the 1500s; in New Orleans and other areas of the American South, a go-cup has meant "a disposable cup for a takeaway alcoholic drink" since 1980, if not earlier. Go-go, which was popularized in the mid-1960s to describe "a type of nightclub or discotheque in which dancers are employed, esp. to dance in a sexually provocative or erotic way," was first employed in the early 1950s to mean "characterized by boundless energy"; by 1967 it was being used to describe speculative stocks and money funds.

Go-go boots by designer André Courreges, circa 1964.

Surprisingly for such a compact, energetic, and versatile word, go showed up late in brand names. Of the nearly 11,000 names with go in the U.S. trademark database, the oldest – mostly for technical products, like Bendix's GO-NO-GO, a testing device – date back only to about 1960. Even more surprising: The majority of the 1,000 most recent trademark applications have been filed since 2016. Examples include VERIZON GO, a mobile data plan; GO SOLAR, a solar-panel installer in Florida; and TIVOLI GO, audio products for use while "on the move and away from home."

What accounts for the surge? Our lifestyles, for starters. When Go-GURT was introduced by Yoplait in 1999 as a children's snack, it pioneered not just a product and a naming style but a category: food that can be consumed with one hand while driving, walking, or (lately) texting. It took the concept of to-go – an American term that dates back to the 1920s – and hypermobilized it.

Yoplait Go-Gurt.

Probably coincidentally, 1999 was also the year the independent movie Go! was released. A comic crime story about a drug deal, the film became a minor cult classic. The Arizona Daily Star's film critic wrote about it: "The writing is go. The performances are go. The film flows like greased go. You don't watch the movie; you go with it. Go, go, go, go and go."

As the new millennium dawned, go was everywhere in the air. The BlackBerry mobile phone, also introduced in 1999, "changed everything," wrote Carmi Levy in The Record of Waterloo, Ontario, the device's birthplace: "Email was no longer something you did at a desk. And being away from the office no longer meant being out of touch." Eight years later, the iPhone went further, putting the internet "in everyone's pocket," as Recode put it. No longer did we have to stay in to watch TV, read a book, or communicate with friends: we could go anywhere and never be out of touch.

For a while, the trendy prefixes i- and e- may have been flashy signposts for this new era, but go communicates what they couldn't: urgency, energy, and, most of all, mobility, real and virtual. (As a culture, we're smitten with journey as a metaphor for just about everything.) Go encapsulates our restlessness, anchors it in Old English, and gives our fads a positive spin. With more than a thousand years of history and richly layered meanings, go is what makes our world go round.

Click here to read more articles from Candlepower.

Nancy Friedman is the chief wordworker at verbal-branding consultancy Wordworking, and the author of a fine blog on naming, branding and more called Fritinancy. Nancy has named a venture-capital firm, a laser hair-removal device, a mobile-money service, and many other companies and products. A former journalist, she still writes or ghostwrites articles, speeches, white papers, and books. Click here to read more articles by Nancy Friedman.

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