What Makes Sense:
By this time, I'm sure you're fully aware that American English is a crazy language. It has pulled so many words and ideas from other languages that it's more of a smorgasbord than a stand-alone language with its own identity. In most independent languages (such as Spanish), a new item, concept, or idea is initially described using adjectives in normal speech. A newcomer, for example, would be described as "an unfamiliar new person." Later, as this idea of "an unfamiliar new person" becomes more firmly cemented in common usage, a form of shorthand is developed to describe it, such as coining a new word like "newbie." You would surely agree that this is a remarkably straightforward procedure. However, American English does not conform.
American English Doesn't Make Sense:
Speakers of American English can't be bothered to follow the same pattern of word development. Although it makes the most sense, using descriptive adjectives with pre-existing words is simply too much work for us. Instead, if we don't have a word to describe something, we simply borrow one from another language. Sometimes, even if a perfectly good one exists, we still invent our own. A "newbie" therefore becomes a "greenhorn," even though the new slang is longer and more complicated. However, perhaps this illogical pattern of laziness isn't entirely the fault of American English. Certainly, American English developed from British English, as the history of the bicycle demonstrates:
The Bicycle's Unfortunate Encounter With English:
In keeping with the English language's reticence to use lengthy descriptions in everyday speech, the English have a tendency to use the shortest word possible when referring to common items. The unfortunate result of this habit is that names for things change over time. For example, when the first two-wheeled personal conveyance vehicle was invented, it was simply referred to as a "bicycle." This "bicycle" had a front wheel that was much larger than the rear wheel. Much later, a different model was introduced that had two wheels of the same size. This new creation was at first known as the "safety bicycle," because it was much easier to learn and use than the original bicycle.
However, as "safety bicycles" became much more common than the original bicycle, everyone began referring to them as simply "bicycles." The intention, of course, was to save time and energy during conversation by not having to use the word "safety" all of the time. However, this required the coining of a new word for the original bicycle, since the word "bicycle" now meant "safety bicycle." Therefore, the terms "penny-farthing" and "high-wheeler" were invented. In an attempt to use the shortest term for the most common item, three new terms were thus created, none of which are now commonly in use (because they are too lengthy to bother saying). In short, by trying to be efficient, the English language simply became even more inefficient.
Here's a visual representation of this crazy pattern of word development in the English language:
The Retronym's Reason for Existence:
Unfortunately, this pattern of coining words is so common in both British (but especially American) English that we have had to--you guessed it--coin another term to refer to it! This bothersome little naming convention of having to go back and re-name something that had a perfectly good name before is called a "retronym," thanks to Frank Mankiewicz, who coined the term in 1980. Just as you would expect from American English, a "retronym" has nothing to do with similar-sounding words like "acronym" or "homonym." In order to better understand what a "retronym" truly is, you'll need to understand the story of liquorice.
Liquorice's Unfortunate Encounter with American English:
As you may know, my favorite dessert/treat/snack is liquorice*. When Twizzlers were first introduced in the United States in 1845, they were black and had the flavor of real liquorice. However, in the 1970s, the company recognized that many American people disliked the strong flavor of real** liquorice. Therefore, they expanded to flavors such as strawberry and cherry. Around the same time, another candy brand, Red Vines, became well-known for its raspberry-flavored red twists. With these two companies leading the way, an alternative candy thus substituted the flavor and surpassing the popularity of real liquorice.
Besides having a red color instead of black, this new type of candy was not flavored with liquorice plant extract. In fact, this candy had neither the taste nor the color of real liquorice. Under normal circumstances, this confection would be called something else entirely, like "red ropes" or "red vines" (which, at first, they were). In any other language or country, this would have been the end of the story. Unfortunately, since this is American English, our story is far from over.
Since they were considered substitutes rather than supplements, these red-dyed raspberry- and strawberry-flavored confections began to be called "red licorice," and real liquorice was referred to as "black licorice," a North American retronym. However, because of the candy's widespread popularity, American English speakers began looking for the shortest possible term to use in everyday conversation. Since it was too difficult to continually differentiate between "red licorice" and "black liquorice," "red licorice" was shortened to simply "licorice," and "black licorice" was only used when absolutely necessary.
Formerly, the "black" in "black liquorice" would have been redundant and unnecessary (since all real liquorice was always black), but with popularity of "red licorice," the term "black licorice" was now necessary to help differentiate between the different types of confections. Thus, American English once again created more work for itself in a misguided attempt to simplify language. Here is a visual representation of what has happened to the term "licorice":
The Definition of a Retronym:
As we have seen, a retronym is a newer name for an existing thing that differentiates the original form or version from a more recent one. It's a name added "after the fact," which really shouldn't be necessary. It is thus a word or phrase created to differentiate between two or more types, whereas previously no clarification was required before there was more than one type. Unfortunately, "bicycle" and "black licorice" isn't the only example of a newer creation "hijacking" an older term.
Further Examples of Retronyms:
In the days before the invention of sweet solid chocolate for eating, the word "chocolate" was usually used to refer to the hot drink. For a while after the chocolate bar was invented, it was referred to as "bar chocolate," but due to its rise in popularity in the latter half of the 19th century, it eventually laid claim to the basic word. Now, we refer to the drink as "hot chocolate."
Before canned corn was widely available, "corn on the cob" was simply called "corn."
Before Americans started calling their new baked creation a "muffin," "English muffins" were simply known as a "muffin" in southern England, where they originated.
"Bar soap" is a term that was invented to differentiate regular soap from "soft soap," or soap in liquid and gel form.
No one bothered calling a guitar "acoustic" until the invention of the solid-body electric guitar.
Before the introduction of FM radio receivers, all AM receivers were simply just known as "radios."
All televisions used to be black-and-white, so no one thought to call them "black-and-white" until the introduction of color television.
"Gunpowder" was a term in use for centuries until the term "blackpowder" was coined in the late 19th century to differentiate it from the newly-developed smokeless powder which superceded it. The smokeless powder is essentially a form of nitrocellulose, which is more stable than traditional gunpowder. "Guncotton" is a smokeless version of nitrocellulose known as "pyrocellulose."
The term "Cider" used to always refer to alcoholic fermented apple juice until the U.S. started manufacturing and consuming non-alcoholic apple juice, which led to the term "hard cider" to specify the alcoholic version.
Originally, all "barrows" suspended the load on poles carried by two people, one in front and one behind. However, when a one-person, one-wheel version was invented in the 14th century, the term hand-barrow was invented to differentiate the old two-person type.
The retronym is a striking example of what happens when a language is allowed to develop completely without rules, borders, or governing bodies. New words are constantly coined, developed, and then discarded to describe the new and rename the old. Ironically, British English was simply "English" until North American English dialects and British English dialects started to diverge. Therefore, the next time you have to refer to something, please be descriptive. The last thing we need is another retronym.
*Don't be concerned by the official spelling; liquorice is also spelled "licorice," and has nothing to do with liquor. It is not alcoholic. After all, there is also a step in the chocolate-manufacturing process that results in something called "chocolate liquor," which is also not alcoholic.
**Real liquorice is flavored and colored black with extract from the roots of the liquorice plant Glycyrrhiza glabra. Although authentic, this extract can also cause low potassium levels in individuals who over-dose on it by eating too much liquorice at one time. Therefore, many manufacturers create liquorice with anise extract, which does not come with dangerous side effects.