The story
Chosen as a word for producing indistinct background noise because it contains no very sharp or recognizable phonemes: see rhubarb (“noise”).
Etymology from Wiktionary, CC BY-SA 4.0.
rhubarb rhubarb
Today it means: Background noise of simultaneous conversations, none of which is decipherable since the actors are repeating the word rhubarb or other words with similar attributes. Full definition →