—Cf. footnote: etymology of the noun rhubarb.

In British English, the noun rhubarb is colloquially used to denote nonsense.

For example, on Thursday 27^th January 2022, The Guardian (London and Manchester, England) reported that Boris Johnson, Prime Minister of the United Kingdom, said the following to dismiss claims that he personally intervened to help the evacuation of animals during the fall of Kabul, Afghanistan, in 2021:

This whole thing is total rhubarb. […] I can tell you that the military always prioritised human beings and that was quite right.

The use of rhubarb to denote nonsense originated in the theatrical practice consisting for a group of actors in repeating the word rhubarb to represent an indistinct background conversation or the noise of a crowd.

One Alexander McQueen mentioned this theatrical practice in a letter published in The Supplement to A Dictionary of Slang and unconventional English (London: Routledge & Kegan Paul Ltd, 1961), by the New Zealand-born British lexicographer Eric Honeywood Partridge (1894-1979)—Alexander McQueen seems to indicate that this theatrical practice dates back, at least, to the late 19^th or early 20^th century:

Alexander McQueen, an Englishman long resident in the United States, writes thus (on 31 Aug. 1953):
Here’s a genuine one that I’ve never seen recorded anywhere; I’ve been looking for it for half a century! It is the word ‘rhubarb’ used as a theatrical term.
When I was a boy (14–17 years old) I studied dramatic art under a pupil of the famous old actor Hermann Vezin ¹. Although Vezin had been born in Pennsylvania, he flourished in London for years, and studied and worked under Charles Kean ², c. 1852. Kean had received traditions from other actors, and they from others, all the way back to Davenant ³ and Shakespeare. They all took a pride in passing down the genuine Shakespearian acting traditions and ‘business’. One of these was to do with ‘rhubarbing’. When a few actors gathered backstage and represented the ‘noise without’ made by a mob, they intoned the sonorous word ‘rhubarb’. The action was called ‘rhubarbing’, the actors ‘rhubarbers’. (Try the word yourself; it really DOES produce an effect if only two or three work at it.)
I have only met one old-time actor in the United States who knew about this custom; and he was from England.

¹ Hermann Vezin (1829-1910) was a U.S. actor.
² Charles Kean (1811-1868) was an English actor and theatre manager.
³ William Davenant (1606-1668) was an English poet, playwright and theatre manager.

These are, in chronological order, some of the mentions of the theatrical practice consisting for a group of actors in repeating the word rhubarb to represent an indistinct background conversation or the noise of a crowd:

1-: From The Excellent Elliott, about the U.S. stage and film actor Elliott Dexter (1870-1941), by Kenneth McGaffey, published in Motion Picture Magazine (New York City, New York) of February 1919:

Dexter began his stage career as a supe, which is noisy drama for extra, in “The Great Diamond Robbery,” at the American Theater, in New York. He didn’t carry a spear in this dramatic masterpiece, probably because there were no spears to carry, but he did grumble, “Rhubarb, rhubarb, rhubarb” off stage to make up the angry mob.

2-: From Holy Deadlock (London: Methuen & Co. Ltd., 1934), a novel by the English author Alan Patrick Herbert (1890-1971):

At the approach of a goddess by air there would naturally be thunder and lightning and manifestations of alarm among the mortals present. All the lights would go out while the thunder raged and the chorus excitedly rushed about and muttered ‘Rhubarb!’
[…]
There was a loud click from the prompt corner and all the lights went out. Thunder and lightning followed immediately; the crowd moved about in an agitated manner, and said ‘Zeus!’ ‘Rhubarb!’ ‘Some portent!’ and other things provided by the careful author.

3-: From the review of Romeo and Juliet (1936), a U.S. film adapted from the play by William Shakespeare, directed by George Cukor, starring Leslie Howard, Norma Shearer, John Barrymore and Basil Rathbone—review published in the Leicester Evening Mail (Leicester, Leicestershire, England) of Tuesday 13^th July 1937:

Bound by no restrictions of the stage, the splendours of Verona in robes and settings are built up largely by English Oliver Messel, whose name is writ large on the sub-titles.
Again scoring over the stage in scenes such as the brawl which opens the play, the crowds do not stand round the wings muttering “Rhubarb, rhubarb,” but we get vivid shots of terror, interest, excitement among the spectators, while the fight itself—and others later in the film—are desperately thrilling.

4-: The reduplication of the noun rhubarb refers to the noise made by an individual actor in the following from The World of the Theatre, by the British journalist Ivor Brown (1891-1974), published in The Illustrated London News (London, England) of Saturday 20^th November 1937—John Gielgud (1904-2000) was a British actor and stage director:

I would put Mr. Gielgud among the romantics—but with reservations. He does care enormously about meaning. It is actually true that a romantic actor of the grand old style, school, and stature could so bemuse and intoxicate the public by the richness of gesture and of aspect and of the lovely noise that came welling out of his lungs that his audience hardly listened to what he said. If he came on in the appropriate garb and stood in the familiar limelight, he could turn a line of Shakespeare into a roar of “Rhubarb, rhubarb, rhubarb!” for all his public cared. Now, Mr. Gielgud has never been a romantic in that way. He is most scrupulous to make every line yield its true intent and every piece of action significant for the story’s purpose. I call him romantic because he lays so much more emphasis on the poetry of Hamlet the sufferer than on the prose of Hamlet the philosopher, the scrutineer of man, his doings, and his destiny.

5-: From the review by Ivor Brown of Shakespeare’s Julius Caesar, produced by the Royal Shakespeare Company at Stratford-upon-Avon, published in The Observer (London, England) of Sunday 7^th May 1950:

The crowd was admirable, every one of them seeming to act an individual part and not to be a “super” shouting the familiar “Rhubarb, rhubarb” of theatre mobs.

6-: From ‘La Gingold’, “a pen-portrait” of the English actress Hermione Gingold (1897-1987), by Gale Pedrick, published in Radio Times (London: BBC Publications) of Friday 17^th October 1952:

Hermione recalls with glee how the effect of crowd scenes was produced when she was an honorary ‘noises off’ expert. Today, the producer can make his choice from a wealth of recordings in the Effects library. ‘But at Savoy Hill,’ Hermione went on, ‘the unemployed actors had a wonderful time. We’d huddle together in a corner and repeat “Rhubarb, rhubarb, rhubarb” or “My fiddle, my fiddle, my fiddle”—and it sounded like a big scene from some mammoth production.’

7-: From the News Chronicle (London, England) of Monday 11^th May 1953:

Lionel Hale ⁴ tells of a strange remark he overheard at the Old Vic
He wouldn’t say—RHUBARB

My favourite actor last week was an unnamed super in the crowd of “Henry VIII.”
[…]
The christening scene was very rich, all banners and courtiers and mitres and vestments—and a London crowd, in which lurked my favourite actor of the future.
Now stage crowds usually make meaningless noises in their moments of excitement. The word “rhubarb” is the groundbars [sic] of their conversation, with “sausage-and-mash” to provide sibilants. (When crowds get savage they force “Raspberries! Raspberries!” through their teeth.)
But the stage crowd last week in “Henry VIII” was more realistic.
The Archbishop held the infant princess in his arms. Asked her name, he raised his face slowly to the dress circle. “E-liz-a-beth,” enunciated the Archbishop.
And from the excited crowd rose, by some acoustic freak, the clear and manly voice of my favourite actor, the Unnamed Super. Did he say “Rhubarb”? No.
“And a very nice name, too,” said his voice, genially.

⁴ Lionel Hale (1909-1977) was a British theatrical critic, playwright, and radio and television broadcaster.

8-: From A critic gets into the act, by Eve Chapman ⁵, published in the Daily Mirror (London, England) of Tuesday 1^st June 1954:

It will be some time before I recover from making my first West End stage appearance—though it wasn’t much of a part.
All I did was sit among the jury in the Old Bailey trial scenes of Agatha Christie’s “Witness for the Prosecution” at the Winter Garden Theatre.
[…]
I found that actors don’t say “Rhubarb, rhubarb, rhubarb” when they are required to make background conversation.
They make appropriate remarks like “I don’t think he’s guilty” or “Amazing, isn’t it?”

⁵ Eve Chapman was the fashion editor of the Daily Mirror and later the agony aunt for the News of the World.

 

EXTENDED USE

 

By extension, the repetition of the word rhubarb came to constitute or denote any murmurous background noise or meaningless utterance.

This extended use occurs on two occasions in the column Oddly Enough, by the British author and journalist Paul Jennings (1918-1989), published in The Observer (London, England):

1-: Of Sunday 29^th November 1953—writing about some diffuse international lawlessness, Paul Jennings evoked:

the bottomless world-anger of the odd men one passes occasionally in the street, swearing endlessly to themselves, the strange outbreaks of students, pushing trams over in Cairo, shouting rhubarb rhubarb in Bow Street. These people sending secret messages all belong to some nameless, world-wide society of destruction.

2-: Of Sunday 10^th February 1957:

To the ear of imagination, the characteristic sound of London is not the roar of traffic but, rising out of the still air, hovering above the solemn buildings, a vast intermingled mumbling—the proceedings of endless Societies and Associations and National Leagues and Boards; a kind of social and intellectual rhubarb rhubarb.

This extended use of the noun rhubarb also occurs in What makes ‘pop’ pop, by Dennis Newson, published in the Daily Herald (London, England) of Tuesday 23^rd July 1963:

Professor Hermann de Groot, one of Holland’s leading sociologists, is working in a little house in Utrecht […].
His task is to discover the answer to the question: What makes a hit record?
[…]
What are his conclusions so far?
“The hit song of the present age is related to a basic anxiety complex,” he said.
“Deep down people are worried about such things as the bomb, landing on the moon, a third world war.
“They want to be soothed and that is why the songs from My Fair Lady had such an extraordinary success.”
Professor de Groot has this tip for song-writers: “Concentrate only on the first five words.
“After that you can repeat ‘rhubarb . . rhubarb . . rhubarb’ for all anyone cares.
“I’m sure of this. Seventy-two per cent of the young people I have seen cannot get beyond the first line.”

Note: First recorded in the late 14^th century, the noun rhubarb is from Anglo-Norman and Middle-French forms such as reubarbe, rebarbe and reu barbare (French rhubarbe), themselves from post-classical Latin reubarbarum, rheubarbarum.

The Spanish archbishop and Doctor of the Church Isidore of Seville (c.560-636) wrote the following in Etymologies (Isidori Hispalensis Episcopi Etymologiarum sive Originum Libri XX):
—translation 2006: Stephen A. Barney, W. J. Lewis, J. A. Beach and Oliver Berghof [the Latin words are in square brackets]:

Rhubarb [= reubarbara], or reuponticum, takes these names because the former is gathered across the Danube on barbarian [= barbaricus] soil, the latter is gathered around the Pontus (i.e. the Black Sea). It has further the prefix reu, because that is “root” [= radix], as if the terms were radix barbara and radix Pontica.

In fact, the post-classical Latin forms are from Hellenistic Greek ῥῆον βάρβαρον (= rheon barbaron), composed of ῥῆον (= rheon), meaning rhubarb, and βάρβαρον (= barbaron), neuter of βάρβαρος (= barbaros), meaning foreign.