A few years ago, Prince Charles addressed a news conference on the peril of American English, which, he said, tends to “invent all sorts of new nouns and verbs and makes words that shouldn’t be.”

To say some words should be, while others should not be, pretends that discrete and verifiable meanings exist for each proper word. Improper words, like “prioritize” and “hopefully” claim to mean something that just doesn’t make sense. But real prescriptivist grammarians, the experts whose opinions are quoted by sticklers like Prince Charles, have long felt free to change the meanings of words, making distinctions that did not previously exist. H.W. Fowler defined the difference between “masterful” and “masterly” in 1926, and his distinction is now taken as gospel.

These little controversies mean a great deal, at a political level and at a personal level. Robert MacNeil and William Cran begin their study of American cultural politics, “Do You Speak American?” (Doubleday, 228 pages, $23.95) with a discussion of prescriptivism. But Messrs. Cran and MacNeil – of PBS fame, and whose companion documentary to this book airs on PBS early this week – take a decidedly laissez-faire attitude to language. Their survey of the linguistic scene touches on black English, the – in their minds – exaggerated rise of Spanish, and on the postwar abandonment of the mid-Atlantic accent. It concludes, in each case, that language is going to take care of itself.

But whatever power language has to self-regulate depends upon people taking it seriously, both as a marker of heritage and an arena for personal taste. What Mr. MacNeil calls “the language wars” is really a debate about how seriously we should each take our own vision of language.

Highbrow writers typically assume that they have the right to tell others how to use words. This slightly presumptuous attitude is both embraced and parodied by the new Oxford American Writer’s Thesaurus (Oxford University Press, 1,089 pages, $40). Amid the standard reference-ese that prescriptivists traditionally hide behind, a host of famous writers have contributed “Word Notes” of their own, injecting solemn advice with swagger and strut.

These “contributing editors” include David Foster Wallace, the novelist who has written at length about usage before; Stephin Merritt, the rock star who always rhymes; esteemed critics Francine Prose and Michael Dirda; and others. But this book shows that, because language is so personal, it’s actually less appealing to get your word choices from a famous personage than from an anonymous editor.

Some of these “Word Notes” are most interesting as tidbits of conceit. Take Zadie Smith’s entry on “pulvinate,” in the Oxford American Writer’s Thesaurus. Ms. Smith laments the overuse of “pillowy.” Instead, “there is a readymade word for the occasion; Latinate, graceful, specifically intended for things that are cushiony and cushionlike, that swell and bulge. The pulvinated face of a drunk, the pulvinate curve of your lover’s breast . . . Much better.”

Much better in what way? Is “pulvinate” more communicative? Does it actually embody the qualities of a soft breast? No. Better because it’s Latinate? In Latin, “pulvinus” is a pillow, so we’re back where we started. “Pulvinate” is better, apparently, because it’s rare. But isn’t the allure of esoteric knowledge in how it’s gathered? The great writer, having traveled much in realms of gold, brings back her exotic finds. Her vocabulary reflects her resume and her interests. A thesaurus is a kind of spoiler.

Many of the contributing editors seem aware of their slightly embarrassing position. Mr. Merritt resorts to some rhyming entries. Mr. Wallace tries, in his assiduous way, to lighten the mood of his pedantic notes by, several times for example, throwing in the slang-word “boner” – “it’s a boner to use even this sense of beg with question unless you’re talking about a true petitio principii.” But even this is coyly arcane: Mr. Wallace uses boner to mean a mistake, as in pre-war sports journalism, not an erection.

Other writers are too cool to bother with new trends. Ms. Prose, writing about “adult,” remains aloofly vague: “Somewhere along the line, this word has, so to speak, outgrown its limited association with biological age. … it’s come to mean sex in general….I assume that’s supposed to mean that such forms of recreation, like sex itself, are the sole province of adults. … Or perhaps it’s meant as a warning to children.”

All Ms. Prose has accomplished is to signal that she knows what we all know. It’s gratifying if “Adult Movies” is a pet peeve of yours as well, but it hardly helps us to find the right word, as a thesaurus should.

The best word notes here really do make a useful distinction, though, telling us something that wouldn’t fit in the diction of reference-ese. For example, Ms. Prose admires “prescience” because “you can use it to describe a predictive knowledge of the future . . . without sounding as if you believe in ESP, or some other such hocus-pocus.”

Contributor David Auburn, who won a Pulitzer Prize for his play “Proof,” admires any word that is onomatopoeic. On “torpid”: “I picture a hippo lolling around in shallow river water. … The word is therefore extremely useful for describing, say, a writer sitting around sending e-mail or playing video games when he ought to be working; and as a self-rebuke and spur to creative activity for that writer.” On “bleary”: “There is in the English language no better word for talking about hangovers.”

Indeed, Mr. Auburn is one of the few contributors who seem to keep in mind that this thesaurus is tailored to suit writers – of fiction, as editor Richard Goodman’s Flaubert-quoting introduction makes clear. David Foster Wallace seems to have forgotten this when he writes that “using utilize makes you seem like either a pompous twit or someone so insecure that he’ll use pointlessly big words in an attempt to look smart” -half of Mr. Wallace’s characters use pointlessly big words, for precisely these reasons.

It is the poetic uses of a word – its resonance, its ironies – that a thesaurus always flattens. That is exactly why a few good poets could round out a project like this. Only David Lehmann, more anthologist than poet, makes the cut, and Mr. Lehmann’s relationship to words is primarily sociological. He writes that “edgy” is a “fake word,” admitting this insight comes from David Brooks’s column in “today’s paper (October 25, 2003).” Mr. Lehmann is formidable: “I remember the year everyone began using the word ‘edgy.’ It was 1996.”

But the great bogeyman in this lexical comedy, the fell wordish hipster, is Simon Winchester. Author of a bestseller about the Oxford English Dictionary, Mr. Winchester not only appears this season in the OAWT, but also wrote the foreword to a small, delightful volume entitled “In Other Words” (Walker & Co., 128 pages, $14), a collection of supposedly untranslatable words, explained.

“Miljo,” the Norwegian word for “society,” also means “environment.” “Glauque” is a French word for sea green that always connotes trouble and bad health. The Lebanese word for “now” is ” ‘hella’, which actually means ‘presently, when I’m done, later.'” Some words are so close to proper nouns they hardly merit inclusion, like “vodnik,” a malevolent Czech water spirit. The supposedly most untranslatable words, like the African “ilunga,” are simply the words with narrowest and hence hardest to explain, meanings.

Prince Charles is somewhat over serious; Mr. Winchester is fanatical about words, but he lacks the prince’s sense of moral meaning. For Mr. Winchester, all is spectacle. Mr. Winchester, who began his career writing about former colonial properties, equates “wonder” with “oddities” in his foreword to “In Other Words.” In the OAWT, Mr. Winchester writes that “Chrism” is a word “I think of as one of the prettiest in the tongue.”

These are the words of a man who thinks of his language as a cuisine. He savors it in the way that will seem most obnoxious, and preposterous, to those who cannot afford to join him at the table. Like Zadie Smith, Mr. Winchester likes the words most likely to draw attention to themselves. Who let these Brits in to spoil our American Writer’s Thesaurus?

Word choice is truly one of the most exciting things in the world; inventing new uses for words, in divergent dialects and untranslatable foreign words, generates genuinely new meaning. But word choice is really more intuitive than can easily be put in a quick “Word Note.” The OAWT is a great exercise in “telling,” while a poem is an exercise in “showing,” as far as finding the right word goes. This new book’s best moments all concern strict matters of usage, and are contributed by Bryan Garner, whose Dictionary of Modern American Usage will better please serious writers.