Keeping Up With Compound Words


These ungovernable liaisons challenge regular humans and copy editors alike. Or do I mean copyeditors? Hmm. As you will see, compounds are slippery, changeable things. A thank-you to poet Ruth H. for her inquiry.

First, what is a compound word? There are two kinds: permanent—the main focus of this discussion—and temporary.

Permanent vs. temporary compounds

A permanent compound may be a single word made up of two words, two words connected by a hyphen, or two words written separately, but in any case it expresses a single idea. Outhouse, stepping-stone, and credit card are all permanent compounds. Now and then you’ll encounter a three-word compound, such as commander in chief.

Temporary compounds normally express two separate ideas and join forces, via hyphen, only when modifying something. The hyphen prevents ambiguity. Take old-book collector. Without the hyphen, the phrase would be readily interpreted to mean an aged collector of books, rather than a collector of old books.

Words created by the addition of a prefix or suffix are also considered compounds.

No broad rule

No one should feel bad about being confused by compounds, permanent compounds in particular. The problem is, there is no broad rule for when they should be expressed as one word (aka closed, or solid), hyphenated, or written separately. So inconsistencies abound—it’s not your imagination. Even dictionaries differ.

You see, it’s the tendency in the English language for frequently used sets of words that express a single idea to become more and more readily understood as a unit and finally to fuse. So a noun modified by an adjective or another noun evolves into a single noun with a specific meaning—a truly new word. Data base rapidly became database, for example. Sometimes there is an intermediate step, the hyphenated compound. One sign that a compound has fused into a single word is that the stress has moved to the first syllable, as in a dark room versus a darkroom.

Dictionaries get updated only so often and may fall behind on evolving usage. Not everyone realizes this, but dictionaries are not prescriptive. That is, it is not their priority to dictate how words should be used. Rather, they are carefully researched to reflect how words are in fact being used. So a dictionary revised in 1990 reflects usage in 1990, and a handful of words may have evolved since then. Words continuously spring forth, change, die . . . sometimes whether it makes sense or not.

Example: Web site vs. website

In Merriam-Webster’s Collegiate Dictionary, 11th edition, released in 2004, it’s Web site. In the American Heritage Dictionary, 5th edition, released in 2012, website is the first listing.

This is a classic case of a compound that is fusing into a single word with a specific new meaning. Increasingly, too, web is not capitalized. The web has become too everyday to treat as a proper noun—it would be kind of like capping telephone.

Example: home owner  vs. homeowner

You won’t find homeowner in Webster’s 11th, but you will find it in the updated American Heritage Dictionary. Since Webster’s 2004 release, the fused form has all but taken over. This is a casual observation, but the trend seems have arisen during the housing boom, when home and own cozied up to each other with perhaps unprecedented frequency.

Unlike website or darkroom, this fusing makes no sense. It creates no new meaning. It makes about as much sense as carowner or dogowner. Another problem with it is that the beginning can be read as the prefix homeo, “same,” as in homeostasis. Nevertheless, there it is: homeowner, and even homeownership, everywhere you turn. I still resist it.

Plenty of permanent compounds are evolving into one-word nouns as I write, many of them more sensibly than homeowner. You see treehouse a lot, for example, but that has precedents in such words as doghouse and whorehouse. There are probably dictionaries that do list it as a single word. I’ll bet lightbox is common—it makes sense to close it up given the potential to misread the open form as “a box that is not heavy.” You see both copy editor and copyeditor.

But, a broad guideline

By now, you can see why there’s no broad rule for handling compounds. All you get is a broad guideline: Hew to current usage so as not to give your reader pause, and be consistent in your own writing.

Despite what I said earlier about the limitations of dictionaries, in most cases they (and not a spell-checking program!) are still the best way to determine current usage. If you’re not sure whether a compound should be one word, two separate words, or hyphenated, look it up in a relatively recent dictionary. If it’s in your dictionary as one word and you use it that way, you’ll be in good company. If it’s not in the dictionary at all, it’s not widely accepted to be a single word and is better left open.

In Webster’s 11th, you’ll find hatbox, rowboat, housedress, taxpayer, lightbulb, litterbug, spiderweb, flatcar, and newspaper, but litter box, light box, tree house, tax base.

There are exceptions, of course!

If your reading tells you that your dictionary is out of date on a particular compound (and the new word isn’t stupid, like homeowner!), go with your experience. Again, just be consistent. Likewise if your industry overwhelmingly favors a certain form and any other would make you look like a dope.

Also worth noting: An open compound doesn’t necessarily have to be hyphenated when used as a modifier. Consider credit card. I’d argue that this permanent compound is so readily understood as a unit that there’s no chance of misunderstanding a phrase like credit card debt in the way you might misunderstand old book collector. And too many hyphens can be distracting.

Lastly, as with rules—this is for you, poets—guidelines too are meant to be (skillfully) broken. In creative writing, one can potentially fuse open compounds in defiance of current usage to good effect.

Excellent case in point: Cormac McCarthy’s postapocalyptic The Road. McCarthy fuses quite a few words to create compounds that feel unfamiliar, slightly off. The device is subtle but effective. McCarthy’s setting is some unspecified yet not-too-distant future, and for this reader, the new words imply the passage of time. But they also give an impression of breakdown, of the language fraying in the face of unimaginable (well, not to McCarthy) devastation and dislocation.

Whatever the case, we can be certain with a writer as gifted as McCarthy that these mergings are not accidents. And now, I hope, you understand compounds well enough to fully appreciate the effect!

I can’t recommend the book more highly, by the way. I was beside myself with admiration as I read.