I thought I *knew*, as an evidence-based origins account and “official” answer, that the term flack for a public relations officer was closely tied to flak “anti-aircraft fire” — via the intermediate occupational descriptive term flak-catcher for their role in deflecting or absorbing abuse and accusation. And that this was popularized in Tom Wolfe’s essay title “Maumauing the Flack Catchers”. (His flak-catchers were local bureaucrats rather than p.r. agents but the idea was closely related.)
But I wanted to check with something besides my own memory, in scholarly sources or some easily-accessible online approximation thereto.
And so, how disappointing that Dictionary.com gives us a story about some guy named Flack, and no mention of flak except a link in a “words sometimes confused with flack” section.
ORIGIN OF FLACK
1935–40; said to be after Gene Flack, a movie publicity agent
Well! At least some support from Etymonline, though they also give precedence to Gene Flack, but give some skeptical considerations against him.
flack (n.)
“publicity or press agent,” in Variety headlines by September 1933; sometimes said to be from name of Gene Flack, a movie agent, but influenced later by flak. There was a Gene Flack who was an advertising executive in the U.S. during the 1940s, but he seems to have sold principally biscuits, not movies, and seems not to have been in Variety in the ’30s.
Comics I Don't Understand 
I doubt that it’s still common knowledge, but the term “flak” was originally a German WWII acronym, for “FLug-Abwehr-Kanone” (literally: “flight defense cannon”).
P.S. Phoebe’s delight with the word “flack” reminds me of Hobbes’s reaction to “smock“:
Hard not to think of this Calvin and Hobbes. Calvin and Hobbes by Bill Watterson for June 23, 1992 – GoComics
On flak/flack: I’ve always assumed the military derivation, helped greatly by Tom Wolfe’s wonderful essay. It certainly describes my feeling defending the corporate position (which I often had only tangential connection to deciding) in front of a room of upset clients.
The colorful derivation of flack, a PR rep, from flak, anti-aircraft fire, is not borne out by the evidence. Flak is first attested in 1938 and did not come to refer to criticism until about 1968. Flack goes back to at least 1937.
At this point, the derivation from the publicist Gene Flack seems to have the best scholarly support, based on a 1984 article in American Speech. However, it seems that lexicographers were not entirely convinced, and major dictionaries still list the term as etymology unknown. I am using my connections with the lexicographic community to see if I can get a better answer.
Sounds like something for Gerald Cohen’s “Comments on Etymology”. In fact, it almost sounds familiar, like he’s covered it; alas, I sent all my copies to my sister, bowing to the reality that I wasn’t likely to reread them. Of course now I’m sorry! (Ain’t that how it always works?)
@phsiii: I am very impressed that you know about Gerald Cohen and Comments on Etymology. I do not think it has a very large circulation. in any case, I have posted a request for an update to the American Dialect Society listserv, which is read by both Gerald Cohen and Fred Shapiro, who wrote the 1984 article. In fact, Fred has already responded to my request, posting examples that show that Variety was using flack by 1933.
So Gene Flack is to publicity as Thomas Crapper is to toilets?
@Mark in Boston: Scholarly sources discount the theory that crapper, a lavatory, derives from Thomas Crapper. The Oxford English Dictionary states: ”The resemblance to the name of the London plumber and toilet manufacturer Thomas Crapper (1836–1910) is almost certainly entirely coincidental, although the word has long been assumed by many to derive from his name. It is conceivable that association with his name appearing on branding on toilets could have helped reinforce the word’s currency, although it is notable that most early evidence of the word’s use is from U.S. sources.” Instead, crapper almost certainly derives from the older verb to crap, plus the -er suffix.
As for flack, Variety was using it in headlines by 1933, without explanation of its derivation. In 1939, the famous columnist Walter Winchell wrote in his column, “Variety, which is trying to coin ‘Flack’ as a synonym for press agent (without much luck) might like to know it was born in the Chicago offices of Gene Flack, a film publicist.”
So where we currently stand is that (as all agree) flack means a press agent, publicist, or public relations representative – all more or less synonymous terms. The theory that it derives from flak, an anti-aircraft gun (the original meaning in German) or anti-aircraft fire (the usual meaning in English), is excluded by the history of its usage. Walter Winchell claimed that it derived from the name of Gene Flack, but this was a few years after the term first came into use and did not come from the people actually using the term. Experts do not find this entirely convincing, but do not have a better origin to put forward.
Flak-catcher, as popularized by Tom Wolfe, does derive from flak, but does not show up until 1970. Flack is not a contraction of flak-catcher, notwithstanding Wolfe’s imaginative suggestion, even though a flak-catcher may well be a flack (although, if I recall correctly, the flak-catchers in Wolfe’s book generally were not publicists).
One other possibility that may be worth mentioning: according to Merriam-Webster, another rumor holds that it derives from a similar-sounding Yiddish word for someone who talks about someone else’s affairs. That seems to me to have more plausibility than the Gene Flack theory. However, I will post further if there is any additional information.
Many thanks, Usual John, for this digging into etymological resources!
And here is the follow-up episode of the strip:
(Which does not use the term flack.)
@Usual John: That seems to confirm that Gene Flack is to publicity as Thomas Crapper is to toilets, because each person had something to do with the respective subject and was erroneously credited with lending his name to some aspect of the subject.
Another famous Flack is Roberta Flack, but we do not call singers “Flacks”.
Ancestry.com says that “flak” is a Middle English word meaning “sod turf block of peat” and thus “Flack” may perhaps possibly conceivably have been an occupational name for a peat cutter. Which might make sense if we called peat cutters “flacks” like we call horseshoe makers “smiths” but we don’t.