The publication of “Fashion Dictionary,” a paperback guide to all things garment-related, contains more than 4,500 entries penned by 134 Italian contributors (Baldini Castoldi Dalai editore, 1,356 pages, $49.50).

But this book is far from a research tool. There is something marvelously dreamlike about “Fashion Dictionary,” in which the black leather jackets favored by Marlon Brando and James Dean are identified as blousons and the French poet François Villon is a brand of shoes. In these pages, the garment district, not the financial one, is credited with being “the center of the most important economic activity” in New York City.

Only some of the dictionary’s entries stop at brief definitions. For instance, the shoulder strap (thin, thick, spaghetti), having been classified in terms of function, is analyzed in a way likely to conjure visions of sultry afternoons in sensual cafés. “Worn under a skimpy or open shirt, under a jacket, or over bare shoulders, the strap often slips off the shoulder down the arm, where it may be left to sit fashionably or hitched back over the shoulder in a quick and irritated gesture or in a slow and provocative manner.”

Though generously illustrated with black-and-white sketches, many by famous designers, “Fashion Dictionary” is an overwhelmingly literary, rather than visual, enterprise. It is not a book in which a definition of a cloche hat is accompanied by a photograph of the same. The choice of entries is also confusing. There is a long essay about shirts, but none about shoes. “Headbangers,” however, are wittily dispensed with: “Generic term used, in absence of a better one, to describe heavy metal fans.”

There were no headbangers milling about the book’s launch party at Rizzoli earlier this month. Michael Macko, the men’s fashion director of Sak’s Fifth Avenue, discussed the book’s utility for the fashion industry, as well as for the public. It was in these pages, he said, that you could discover the difference between “bespoke” and “made-to-measure.”

“What is the difference?” someone asked, to general laughter.

“Buy the book!” Mr. Macko shot back.

In fact, “Fashion Dictionary” contains no entries for “bespoke” or for “madeto-measure.”

Dense with scholarship on every aspect of fashion, it is an eccentric, engagingly continental book at least as fascinating as it is useful. Enraptured by the poetics of costume, its authors can nonetheless be surprisingly cold-eyed about their chosen subject. “Elegance,” one tells us, “is a gift — sometimes undeserved — and is independent of social class. … [It] can perhaps best be defined as a distillate of style, equilibrium, sublime simplicity, and maybe, a bit of boredom.”