blah-blah-blah
UK[ˌblɑː blɑː ˈblɑː]US[ˌblɑ blɑ ˈblɑ]
n
Meaningless or tedious talk; nonsense.
interj
Used to represent the sound of someone talking at length in a dull, boring, or incomprehensible way.
Etymology
The term 'blah' emerged in early 20th century American English as an onomatopoeic representation of meaningless or tedious talk. Its reduplicated form, 'blah-blah-blah', intensifies this sense of endless, boring chatter. The word exemplifies a common linguistic process where sounds are created to mimic a concept—in this case, the droning noise of a speaker who is not engaging the listener. It has become a standard lexical item for dismissing verbose or insignificant content in speech or writing.
Analysis
This is a reduplicative onomatopoeic formation, not composed of classical morphemes. It imitates the sound of idle or monotonous speech.
Examples
I tried to read the report, but it was just full of technical jargon and blah-blah-blah.
He went on about market synergies and paradigm shifts, blah-blah-blah, until everyone was bored.
"And then she said I was being unreasonable, and I said... blah-blah-blah." She waved her hand dismissively.