Twitter was all, ah, atwitter last week because a new edition of a dictionary came out, adding about 2,000 words to the “official” English language. Among those words were “chillax,” “cool hunter,” “turducken,” and “vuvuzela.”

On Twitter, and in some media stories, the new dictionary was variously named as the The Oxford English Dictionary, The New Oxford American Dictionary, The Oxford Dictionary of English, and simply, The Oxford Dictionary.

Only one of those is correct, and therein lies a problem.

The dictionary that “legitimized” these words was The Oxford Dictionary of English, which debuted in 1998, as the, um, New Oxford Dictionary of English. It’s not the same dictionary as any of the others, though many of the same words are in all of them, and they all share the Oxford name. There are also “compact,” “abridged,” and “concise” versions of those dictionaries, as well as versions for various parts of the English-speaking world.

Dictionaries, like cars, have many models that are designed for different audiences. Want
historical usage and the etymology of a word? The OED is the granddaddy, in that it never deletes definitions or uses, only adds to them. Want to know how words are used in the United States? NOAD might be for you. Want to know how words are now being used anywhere English is spoken, regardless of local usage? The ODE could be the one you want.

For Americans, “Webster” is the word that immediately brings to mind dictionaries. Here, too, confusion reigns. Webster’s New College Dictionary, Merriam-Webster’s Dictionary, Merriam-Webster’s Collegiate Dictionary, Webster’s (First, Second, Third) International Dictionary, Random House Webster’s Dictionary, Random House Webster’s Unabridged Dictionary … well, you get the idea.

How to choose? Part will depend on what you want the dictionary for. If you just want to know how to spell a word, almost any dictionary will do, as long as it’s less than ten years old or so. (Almost no one spells it “employe” anymore.) If you want to know what a word means, though, you start getting into the realm of choice. Some dictionaries don’t admit new words until they’re firmly established in common usage. That helps explain why “vuvuzela” made it so quickly: The World Cup this year exposed millions of people (some unhappily) to the sound of and word for the horn that is traditionally blown by fans at soccer matches in Africa. Some keep all definitions, others delete ones that are no longer “au courant.”

Some words are not really “new,” but just new to that dictionary. “Turducken,” for example, which is a chicken stuffed inside a duck stuffed inside a turkey, has been around by that name at least since the 1980s, and had probably been sampled around Louisiana for a lot longer.

Some dictionaries are much more liberal in accepting new words, even if they have not reached “common” status. (In less liberal moments, I call those “slut dictionaries.” You can figure out why.) There is nothing wrong with those dictionaries, but taking them as gospel may not be appropriate for publications that reach diverse audiences. “Cool hunter” (someone whose job is to seek out the latest trends) and “chillax” (a conflation of “chill out” and “relax,” pronounced chill-AX), may produce only confusion in many readers. And it’s probably not a good idea to use a word if you have to search for a dictionary that includes the meaning you’re using. That’s why publications will usually have a “house” dictionary, so everyone is literally on the same page.

The dictionary favored by the Associated Press and many news publications, Webster’s New World College Dictionary, tries to walk the line between fad and fuddy-duddy. Though who uses “firetruck” is a mystery.

Ends today: If you'd like to help CJR and win a chance at one of
10 free print subscriptions, take a brief survey for us here.

Merrill Perlman managed copy desks across the newsroom at The New York Times, where she worked for 25 years. Follow her on Twitter at @meperl.