Since ancient times, speakers of every language have made up nonsense syllables to indicate contempt for what other people were saying to them.
We’ve even inherited the ancient Greek nonsense syllables bar-bar-bar in the word barbarian: The Greek word barbaros meant “foreign, strange, ignorant.” According to the OnlineEtymology Dictionary, the word barbaros was an onomatopoeic formation echoing the unintelligible speech of a foreigner.
The most common nonsense syllable used to represent empty talk in the United States is blah:
The earliest OED documentation of blah in the sense of “meaningless, insincere, or pretentious talk or writing; nonsense, bunkum” is 1918.
Blah is usually repeated when the sense is “empty talk”:
When big data is just so much “blah, blah, blah”
Getting Past “Blah, Blah, Blah” When Talking to Prospects
Sometimes a single blah means the same thing:
I’ve been overwhelmed by the amount of jabber in the world – it’s a vast cloud of blah.
As a plural noun, “the blahs” are a state of despondency:
You’ve got the blahs. You’re not feeling hopeless, but you’re not feeling good either.
As an adjective, blah means “lethargic, unenthusiastic, listless, or torpid”:
What to Do When You Feel Blah About Your Job
“Blah, blah, blah” recently found its way into the news when a political candidate in Oregon blasted a newspaper reporter who demonstrated his lack of interest in what another candidate was saying by writing down “blah, blah, blah” instead of her actual words.
And perhaps the longest sequence to date of this string of nonsense syllables occurs in a television ad in which actor Gary Oldman holds a telephone to his ear and says “blah blah blah” for five seconds straight.
Another set of nonsense syllables is “yada yada yada.” Variations of this utterance are documented in the OED beginning in 1947. I first heard it on the Jerry Seinfeld show where I understood it to mean “details too boring to mention.”