Definition

/blɑː/

noun

Nonsense; drivel; idle, meaningless talk.
(in plural, the blahs) A general or ambiguous feeling of discomfort, dissatisfaction, uneasiness, boredom, mild depression, etc.

verb

adjective

Dull; uninteresting; insipid.
“Well, the new restaurant seems nice, but their menu is a little blah.”
Low in spirit or health; down.
“I decided to go exercise rather than sit around all day feeling blah.”

interjection

An expression of mild frustration.
“Blah! Why can't I get this computer to work!”
(When spoken repeatedly, often three times in succession: blah blah blah!) Imitative of idle, meaningless talk; used sometimes in a slightly derogatory manner to mock or downplay another's words, or to show disinterest in a diatribe, rant, instructions, unsolicited advice, parenting, etc. Also used when recalling and retelling another's words, as a substitute for the portions of the speech deemed irrelevant.
“And then he was like, "Oh, my brother's an Internet millionaire, blah blah blah." Like I care!”
Representing the sound of vomiting.