Of Australian-English origin, the noun plonk denotes cheap wine of inferior quality; also, more generally: wine or alcohol of any kind.
—Cf. also ‘Château Plonk’: meaning and origin.
ORIGIN OF PLONK
The noun plonk is an alteration of the adjective blanc in the French noun vin blanc, denoting white wine.
This ultimately goes back to the slang of the soldiers who were stationed in France during the First World War. In Digger Dialects: A Collection of Slang Phrases used by the Australian Soldiers on Active Service (Melbourne and Sydney: Lothian Book Publishing Co. Pty. Ltd., 1919), the Australian barrister and lexicographer Walter Hubert Downing (1893-1965) recorded the following expressions relating to wine:
POINT BLANK—See VIN BLANC*.
VIN BLANK (Fr., vin blanc)—White wine.
VIN ROUSH (Fr., vin rouge)—Red wine.
VON BLINK—A humorous corruption of vin blanc.
[* Here, VIN BLANC is probably a misprint for VIN BLANK. Incidentally, the noun plonk does occur in Walter Hubert Downing’s Digger Dialects of 1919, but is defined as “an artillery ammunition column”.]
A rhyming-slang form, plinketty-plonk, was mentioned by the British journalist, travel-writer, essayist and novelist Stephen Graham (1884-1975) in Ways of Thinking and Talking, Chapter 7 of A Private in the Guards (New York: The Macmillan Company, October 1919)—this book is an account of the author’s wartime experience in the Scots Guards:
During the German advance on Château-Thierry and their frustrated efforts near Rheims, a comrade looked over my shoulder at the map in a copy of the Paris Daily Mail.
“Thank God, they haven’t taken Epernay, that’s where the Plinketty Plonk (vin blanc) comes from. That would have put the lid on it! And I see they haven’t got Meaux; that’s where the beer comes from, isn’t it?”
In W.H. Downing’s Digger Dialects (Melbourne: Oxford University Press, 1990), a revised and updated edition of Walter Hubert Downing’s Digger Dialects of 1919, Jay Mary Arthur and William Stanley Ramson explained as follows the evolution from the French noun vin blanc to the English noun plonk:
Vin blanc has been used in English since 1814, but was borrowed freshly by Service personnel in WWI. Vin blank, point blank, and von blink exemplify the word-play which led finally, via plinketty plonk (rhyming slang), to plonk.
EARLY OCCURRENCES OF PLONK
In the sense of cheap wine, the noun plonk seems to have originated in the state of South Australia.
The earliest occurrences of this noun that I have found are as follows, in chronological order—the first two are credited to the Australian politician Clement Reuben Collins (1892-1959), who, from 1924 to 1933, represented Murray in the South Australian House of Assembly:
1-: From the account of a parliamentary debate on the taxation proposals of the Government of South Australia, published in The News (Adelaide, South Australia) of Thursday 8th December 1927:
A characteristic contribution to the debate was made by Mr. Collins. He objected to the Government “plonking on” the taxation.
“Give us a definition of ‘plonk’?” asked Mr. McMillan.
“Yes, I can do that,” replied the obliging Mr. Collins.
“It is a cheap wine produced in Mr. Crosby’s district.” Loud laughter greeted the sally.
2-: From The Register News-Pictorial (Adelaide, South Australia) of Thursday 31st October 1929:
Coffin varnish and plonk were two of the names by which Mr. Collins (Lab.), in the Assembly yesterday, referred to some of the cheaper wines produced in S.A.
3-: From The News (Adelaide, South Australia) of Friday 9th May 1930:
“Plonk” Defined to Court
“Plonk” was added to the vocabulary of those who attended at Port Adelaide Police Court today.
In giving evidence Plainclothes Constable P. Reidy stated that a man said that he had a bottle of “plonk” in his possession.
Inspector J. E. Noblet—Did you know what he meant?
Witness—Yes. A bottle of cheap wine.
“In other words, a bottle of ‘pinkie,’” said Mr. J. H. Richards, who was on the Bench.
4-: From The Barrier Miner (Broken Hill, New South Wales) of Tuesday 10th February 1931:
Following on a young man entering on a mad career in a motor car last night while allegedly under the influence of cheap wine, he found himself in the Police Court this morning. […]
[…] Defendant had been drinking “plonk,” or cheap wine, alias “pinky.”