The phrase not to give a XXXX (also a xxxx, a four-X, a Four-X and a Fourex) means not to care at all, not to give a damn, XXXX being a euphemistic substitute for a four-letter swear word, usually fuck.

The earliest instance of the phrase that I have found is from an advertisement for the New Musical Express (NME), published in the Daily Mirror (London) of 3^rd February 1972:

VIV STANSHALL’s only one of the regular names in NME these days. It’s coming up strong as a thinking music paper with the widest brightest reporting in the business. Try it this week for the first of 5,000 words of self-analysis by MARC BOLAN of T-REX on “I Don’t Give a xxxx So Long As I Can Boogie”. DR. JOHN. A GRACE SLICK exclusive. CAROLE KING. YES.

The second-earliest instance of the phrase that I have found is from the Rapid City Journal (Rapid City, South Dakota) of 8^th November 1972:

     Editor’s note: The following was addressed to the Rapid City Boys Club.
Hello Fellas:
     I know a few of you know who I am and some don’t, and some don’t give a XXXX.
   To introduce myself, I am PV2 Thomas C. Westin; I am private 2^nd class in the U.S. Army. I have been a member of the Boys’ Club since 1961 or 1962 (can’t really remember); anyway, since I was 7 years old and I am still a member now.
&c.

Another early instance is from The Evening Press (Binghamton, New York) of 15^th November 1972, which published a letter by Herman Stahl, “a pastor, parent and patriot”:

May I ask why newspapers (including the Binghamton Press) print many of the filthy words included in remarks and interviews on a local, AP and UPI level? Such “cussing or slanguage” used to be left blank, where spoken. Now, it is common-place printed matter!
[…]
I’d be ashamed to offer myself for public office with such a slogan as, “He gives a xxxx.” I understand that the coiner of that (or bearer of said slogan) is an experienced mayor, parent and educator. Political slogan or no, I think it unwise and unnecessary wording. Surely, he values virtue over a vote!

The phrase was also used in the Daily Independent Journal (San Rafael, California) of 10^th July 1974 about the discrepancies between the transcripts that President Richard Nixon issued of his taped conversations and those taken from the same tapes by the Judiciary Committee for use in its impeachment inquiry:

The Judiciary Committee transcript quotes Nixon as telling John W. Dean III: “I don’t give a xxxx what happens. I want you all to stonewall it, let them plead the Fifth Amendment, cover-up or anything else, if it’ll save it – save the plan. That’s the whole point.”

 

MISTAKEN ETYMOLOGY

 

The Oxford English Dictionary (OED – 3^rd edition, 2004) erroneously states that not to give a XXXX originated in a series of British television advertisements for Castlemaine XXXX [see note], a brand of Australian lager; the OED quotes The Sunday Times of 11^th August 1985, which mentioned the fact that the advertising agency Saatchi & Saatchi had conceived this slogan for Castlemaine XXXX:

Australians wouldn’t give a XXXX for any other lager.

And the earliest instance of the phrase in the OED is from The Times (London) of 19^th August 1985:

Is it not inconsistent to condemn Botham* for publicly saying he does not give a XXXX for the opinion of an umpire?

(* the English cricketer Ian Botham (born 1955))

The following details given by The Observer (London) on 8^th September 1985 show that, indeed, the use of the phrase from the early 1970s onwards was unrelated to the British advertising campaign for the Australian lager, which only began in the mid-1980s:

Allied-Lyons has been heavily promoting Castlemaine XXXX since its launch in May 1984, through a lavish advertising campaign masterminded by Saatchi & Saatchi using the slogan ‘Australians wouldn’t give a XXXX for any other lager.’

This campaign was a success, as The Observer (London) explained on 30^th November 1986 about the winners of the annual ‘Advertising Effectiveness’ awards given by the Institute of Practitioners in Advertising:

Allied Breweries has revealed that its ‘Australians wouldn’t give a XXXX . . .’ advertising has helped its Castlemaine XXXX lager build sales of £150 million a year, over half of which is extra business for Allied, rather than people switching from other Allied beers.
As it happens, the winners are often campaigns that have also won creative awards, thus demonstrating that ads can be both entertaining and effective. The Castlemaine XXXX campaign, by Saatchi & Saatchi, won the top creative honours at this year’s poster awards and has also picked up awards for its TV commercials.

Therefore, although the phrase not to give a XXXX did not originate in those advertisements, it gained currency in British English because of them. Their influence is clearly shown by the following from The Stage (London) of 20^th February 1992, about the London Jewish Comedy Show at the Canal Café Theatre in Little Venice:

If inside every stand-up comic there’s a teacher always itching to underline his authority, inside every fat comedienne there’s a skinny intellectual making fun of herself. The bounteously rounded Leelo’s monologue is sharp and funny, beautifully written and crisply delivered, even when she utters the alternative’s obligatory Castlemaine XXXXs for the first and only time in the entire evening.
It is appositely smuggled into context, however. When Leelo asks her old booba on her wedding night how she can best keep her husband happy, and the ancient crone trots out the traditional yiddisher mommer’s bromides, put on your best perfume, your most revealing negligee etc. Leelo stops her short.
“I know how to XXXX” she says. (By now you’ve inserted the necessary letters) “What I really want to know is how to make chicken soup.”

Cf. also ‘refreshes the parts other — cannot reach’.

 

Note: On its official website, Castlemaine XXXX gives this explanation of the reduplication of the letter X; it says that “back in the day”, which seems to refer to the early 20^th century,

beer quality was measured in Xs. The brewery’s first brew produced was XXX Sparkling Ale, which was awarded three Xs. The results were promising, but something was missing. So in 1924, they perfected the recipe further, gaining a fourth X.

 

I have exposed other errors in the Oxford English Dictionary in:
– on errors in the Oxford English Dictionary
– original meaning of ‘to see the elephant’
– the mistaken origin of ‘white elephant’ in the Oxford English Dictionary
– a curious case of misunderstanding in the Oxford English Dictionary
– clew – clue
– the authentic origin of ‘a pretty kettle of fish’
– the multiple meanings and origins of ‘P’s and Q’s’
– The usual explanation of ‘Hobson’s choice’ is fallacious.