Why is "bombshell" used to describe attractive women?

Solution 1:

The OED's first quotation for a bombshell describing a woman is 1942, but it was indeed the title of a 1933 film starring Jean Harlow. In fact, the film was later renamed to The Blonde Bombshell so it's possible Harlow got the nickname from the movie.

(It appears in a number of 1933 snippets in Google Books which could be misdated, but look correct.)

The earliest verifiable example I found is in the Spokane Daily Chronicle - Nov 24, 1933:

But it seems that Mr. [Lee] Tracy stepped out on a balcony in his pajamas and made wild gestures during a Mexico City parade, and now Mr. Tracy, a star with a long list of hits from "Blessed Event" to "The Blonde Bombshell" behind him, is no longer with at least not until things are "straightened out," if they ever are.

And from the UK:

R, H., 1933, Dec 09. THREE NEW FILMS. The Manchester Guardian (1901-1959), 16:

Two of them, "The Cradle Song" and "L'Ordonnance," are by famous authors, the first Sierra and the second Maupassant, and have European stars, but the only completely successful one is the one with the least pretension, "Blonde Bombshell," at the Empire.

The next day's Observer explains the name.

LEJUNE, C.A., 1933, Dec 10. The Pictures. The Observer (1901- 2003), 12. ISSN 00297712:

And it is worth mentioning, in passing, that Hollywood cannot be blamed for the title. It is we, the audience, who have spoilt an arresting and altogether unusual title with that ridiculous adjective. When the film first came out in Hollywood, it was called "Bombshell," tout court. But the public stayed away because they thought it was a war picture. "Blonde Bombshell" was the final compromise between dynamics and security. ...

The story is nothing but a snatched handful of experiences form the life of Lola Burns, star of stars in the Monarch studios. She is their "It Girl," or, alternatively, their Blonde Bombshell--eruptive, starry-eyed, warm-hearted, a little fatuous.

Edit: Bill Mullins found slightly earlier references:

The San Diego Evening Tribune 1 Nov 1933 p 8A col 5 has an ad for the film (titled "Bombshell") with the line "A Blonde Bombshell in the Picture That Has Thrown Hollywood Into Consternation!"

The LA Times of that day has a small ad (sec II p 8 col 5) that reads: "Last Times Today Jean Harlow Lee Tracy "The Blonde Bombshell" as if that were the film's title.

Solution 2:

J.E. Lighter, Random House Historical Dictionary of American Slang (1994) confirms the view expressed by congusbongus (in the original post above) and by Hugo, Talia Ford, and Mari-Lou A (in their answers) that the popular association of bombshell with "exceedingly attractive woman" begins with Jean Harlow's turn as Lola Burns in Bombshell:

bombshell n. a strikingly sexy woman. [First cited occurrence:] 1933 Mahin & Furthman Bombshell (film): I see Lola Burns, the bombshell herself.

A copyright entry for the play that the movie is based on—Bombshell, by Caroline Francke—appears in the Library of Congress's Catalog of Copyright Entries (1932), with a copyright date of October 22, 1932. According to IMDb, the play wasn't produced prior to the release of the Jean Harlow film.

A search of U.S. newspapers in the Chronicling America database (which covers the period from 1835 through 1922) turns up several instance where a female character or a female performer or a group of female performers are identified as "bombshell." From an advertisement for performances at the National Hall, in the [Washington, D.C.] American Telegraph (May 15, 1851):

To conclude with the vaudeville of LOVE IN MASQUERADE. Aurelia, alias Bombshell ------ Mrs. M. Jones. Lucy --------------- Mrs. Cappell. Reserved seats 50 cents; Box seats 37 cts.; Gallery 25 cts.

From "Among Us Mortals, Drawn by W.E. Hill: The Burlesque Show" (a series of satirical drawings of people with fictional identities) in the New-York Tribune (April 1, 1917):

[Caption:] Lilly Romaine, soubrette on the programme as "The Little Bombshell of Joy," living up to her reputation.

From an advertisement for a performance by Flo-Flo and Her Perfect "36" Chorus, in the Ocala [Florida] Evening Call (February 2, 1920):

GORGEOUS GIRLS IN FEMININE FINERY[.] ITS EXHILARATING[,] INVIGORATING[,] INTOXICATING[,] REJUVENATING[.] A Bombshell of Youthful Beautiful Shapely Girlie Girls[.] Replete With Catchy Songs, Tuneful Music, Wit, Humor and Repartee[.] FULL OF PEP–LET'S GO[.] PRICES 77c, $1, $.150 and $2.00 Plus War Tax[.]

There is, in addition, this advertisement for a film at the Please-U Theatre described as a "melodramatic bombshell," from the [St. Johnsbury, Vermont] Caledonian-Record (July 18, 1921):

Maurice Tourneur Offers "THE BAIT" With Exquisite Hope Hampton[.] A Paramount Picture adapted from the stage play "The Tiger Lay." A melodramatic bombshell of love, romance, and mystery. The Lights of Paris! The Shadows of New York all blended in one long thrill. Great supporting cast, all the superb scenic artistry that Tourneur is famous for!

A Google Books search of the period 1900–1932 finds multiple instances in which bombshell is used figuratively to mean "shocking or situation-changing revelation or event," but only one in which an author equates a bombshell with a female human being—and in that one the implication is not of high-voltage sexuality but of tranquility-destroying unpredictability and rashness. From Christopher Morley, The Haunted Bookshop (1919):

"Well?" said Roger, as Mrs. Mifflin made no comment. "Don't you think it will be rather interesting to get a naive young girl's reactions toward the problems of our tranquil existence?"

"Roger, you blessed innocent!" cried his wife. "Life will no longer be tranquil with a girl of nineteen round the place. You may fool yourself, but you can't fool me. A girl of nineteen doesn't REACT toward things. She explodes. Things don't 'react' anywhere but in Boston and in chemical laboratories. I suppose you know you're taking a human bombshell into the arsenal?"

Roger looked dubious. "I remember something in Weir of Hermiston about a girl being 'an explosive engine,'" he said. "But I don't see that she can do any very great harm round here. We're both pretty well proof against shell shock. The worst that could happen would be if she got hold of my private copy of Fireside Conversation in the Age of Queen Elizabeth. Remind me to lock it up somewhere, will you?"

Given the paucity of woman-as-bombshell references in the decades before the film Bombshell appeared in 1933, it seems unlikely that any of the earlier instances noted above had a significant influence on popular usage before the Harlow film appeared. But if nothing else, they show that equating a woman with an explosive device did not originate with Caroline Francke in 1932.

Solution 3:

When Jean Harlow, a platinum blonde, starred in Bombshell in 1933, the term bomb-shell had already been in use for at least 73 years (etymonline.com) in the sense of a "shattering or devastating thing or event." In most of her films, Harlow "was sluttish and smart, cracking gum and one-liners simultaneously: chewing up the scenery as the vulgar star of Bombshell" (Molly Haskell). It stands to reason to conclude that the blonde bombshell, first attested in 1942, was derived directly from Jean Harlow's persona. That, however, is not a felicitous answer to the question of why the filmmakers of Bombshell chose exactly that metaphor over another similar one. Wasn't, say, a volcano, likewise both an event and a thing, just as fitting a metaphor? Its erruption (~ explosion) is shattering. And devastating. Could the bombshell have been, simply, an arbitrary choice? Not likely.

It had been only 15 years since the end of the Great War, and the notion of sudden devastation by bombing was still omnipresent, what with all the unexploded bombshells strewn around England, not to mention the Western Front ("iron harvest"). Devastating and love (a common euphemism for passion) often go together and always have. And then, there was also the shape of the thing—the thing—which might've been an additional reason why not the more frequent word bomb was chosen, but rather the bombshell, the former having some, whether more or less, abstract realizations, and the latter certainly being more denotative of a thing, of an object, i.e., of the woman-object. The bomb was waved aside despite its not yet having become burdened by the secondary meanings of success, a failure, a marijuana cigarette, a large sum of money (all those meanings sprung up after 1933, according to OED); and despite its being synonymous with bombshell. Interesting. The shape, then. Well, a picture being worth a thousand words:

OK, two words: mammary, phallic.

Here it might be opportune to quote Wikipedia, "The term bombshell is a forerunner to the term "sex symbol" and originally used to describe popular female sex icons. Modern slang refers to a bombshell as an extremely sexually attractive woman."

At the peril of sounding like a feminist, I'll posit that this sort of labeling is a typical male thing. Wasn't the "bullet bra" ("torpedo bra") invented by a man? (Yes it was, by Howard Hughes, no less, in 1941.) That military terminology crept into the civilian life was, understandably, partly due to the vicissitudes of the times, but I think it has just as much to do with the old story of sex and violence. So there you have it.