blah

noun

1. (informal, uncountable)Nonsense; drivel; idle, meaningless talk.
2. (countable, in-plural, informal, uncountable)A general or ambiguous feeling of discomfort, dissatisfaction, uneasiness, boredom, mild depression, etc.
3. (countable, derogatory, informal, uncountable)A fool, an idiot.

adj

1. (informal)Dull; uninteresting; insipid.

   “Well, the new restaurant seems nice, but their menu is a little blah.”

   “He was struck by how much pleasure they seemed to take in their daytime lives, how blah their night work was by contrast, how altogether meaningless; […]”

   “[…] although the show deliberately showcases various luxury goods […], the overall ambience is extraordinarily bare of style and beauty, offering instead a world of blah décor, undistinguished fashions and cavernous homes that just look like overpriced McMansions.”

2. (informal)Low in spirit or health; down.

   “I decided to go exercise rather than sit around all day feeling blah.”

intj

1. An expression of mild frustration.

   “Blah! Why can't I get this computer to work!”

2. 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.

   “Yeah, yeah, blah blah blah, Mom, you said this all yesterday.”

   “And then he was like, "Oh, my brother's an Internet millionaire, blah blah blah." Like I care!”

3. Representing the sound of vomiting.

verb

1. (intransitive)To utter idle, meaningless talk.

   “Ooh, I feel so guilty, I've got far too much money — […] So give it away, endow a charitable foundation, burn it, but stop blahing on about it […]”

   “Someone else said to me: “If you’re writing something again, don’t blah on about winning elections; it really offends them.””