By Michael Herr

Knopf. 158 pp. $18.95

About the only definition of a novel that makes much sense anymore is a jokey one -- that the novel is a prose fiction of a certain length with something wrong with it. On the dust jacket of "Walter Winchell," it states plainly that this is a novel, so what's wrong with it? Michael Herr himself provides the clue when he says in a preface that "Walter Winchell" "began its life as a screenplay and no attempt has been made to conceal its origins from you." That, dear reader, is ultimately what's wrong with it.

It is written in narrative prose, as is Graham Greene's "The Tenth Man," another unproduced screenplay. But no matter in what form, it is unusual to see any unproduced film work published and available in book form. When such writing does find its way into print, the question that immediately occurs is this: Why wasn't it produced as a film?

First of all, there is the matter of identification. Who was Walter Winchell? Herr admits that people under the age of 40 are not likely to know; and he might better say under 50. Although Winchell was essentially no more than a gossip columnist out of New York, he was amazingly influential during the '30s and '40s. It was not just that he was carried in about 1,000 newspapers in his heyday, but also that his weekly radio broadcast -- Broadway gossip, a sprinkling of inside political stuff and little sermons on Americanism -- was for a time the highest-rated show in the land. With that familiar, urgent, hectoring, know-all voice of his, he became as much a celebrity as those that he tattled on. But now that voice is silent and the name can do no more than awaken nostalgic feelings in a few members of the World War II generation -- not a big segment of the movie-going public.

A greater, though subtler, difficulty with "Walter Winchell" as movie material is Herr's attitude toward his subject. He admires Winchell's energy and writes with a kind of matching drive of Winchell's early life -- his years in vaudeville, his brash beginnings in newspapering at the bottom-of-the-barrel New York Graphic. But Herr is too honest and too good a reporter (remember "Dispatches"?) to withhold the worst when his man makes it to the top. The portrait of the mature Winchell that emerges here is of an overbearing egotist who alienates friends and lives on the flattery of sycophants. Nor does Herr soft-pedal Winchell's distasteful collaboration with Sen. Joe McCarthy and Roy Cohn. Still, there is something in the manic style of the man, his wisenheimer attitude, that continues to fascinate the writer to the end. In short, Herr feels ambivalent toward him. And ambivalence won't play in the movies today. As one producer, or maybe more, may have reminded Herr, "Ya gotta have somebody to root for, kid."

Finally, that same producer may also have asked him, "Where's the story?" There's no real crisis here, no turning point, unless it's Winchell's surrender to Cohn, and that comes far too late to make much difference. Except for that, nothing much happens to him; it's much less a "novel" about Winchell than it is a presentation of the public figure he became.

As a piece of reading matter, swift and rat-tat-tat in style though it may be, "Walter Winchell" is repetitious and finally rather dull. It might have served as the basis for a real book, had Herr taken the time to rework the material. But as it is, it's fairly evident that he gave the editors the same manuscript he had been flogging to producers. We understand why the producers turned it down, but why did Knopf accept it?

The reviewer is the author of several books, including "The Beat Generation" and "Dalton Trumbo."