To blow a raspberry is to push the tongue between the lips and blow, producing a rude, spluttering noise that imitates flatulence. It is a gesture of contempt, mockery or dismissal, most familiar as something children do to tease each other, though adults use it too when they want to show they think something is worthless or ridiculous without bothering to argue the point. The noise itself is doing the work here; ‘raspberry’ is simply the name that got attached to that sound, and has nothing to do with the fruit.
What’s the origin of the phrase ‘blow a raspberry’?
The phrase comes from Cockney rhyming slang. ‘Raspberry tart’ rhymed with ‘fart’, and over time the phrase was shortened to simply ‘raspberry’, which came to stand for the rude, fart-like noise made with the mouth. Etymonline dates this “rude sound” sense of raspberry to 1890, describing it as a shortening of the earlier rhyming phrase ‘raspberry tart’. Grammarist places the shortened phrase in the same period, the late 1800s, and treats it as a typical case of rhyming slang dropping its rhyming word, much as ‘bread’ came to stand for money from ‘bread and honey’.
Part of the phrase’s usefulness was that it sounded completely innocent to anyone unfamiliar with its origin. ‘Raspberry’, like ‘berk’ (from ‘Berkshire hunt’), ‘ginger’, ‘hampton’ and ‘khyber’, could pass as a harmless word to listeners who did not know the rhyming slang behind it, even though its true meaning was much cruder. This device allowed British comedians of the post-war period to slip risqué material past the BBC censors, since the word itself gave no obvious offence.
That comic use continued well into television. Spike Milligan was later credited with providing the raspberry sound effects for The Phantom Raspberry Blower of Old London Town, a Two Ronnies sketch he worked on with Ronnie Barker, keeping the noise firmly associated with broadcast comedy long after its slang origins had faded from most people’s minds. The gesture itself needs no explanation to be understood; anyone hearing the sound knows exactly what is meant, whether it comes from a child at play or a performer working for a laugh.