noun

1. Nonsense; drivel; idle, meaningless talk.

2. (in plural, the blahs) A general or ambiguous feeling of discomfort, dissatisfaction, uneasiness, boredom, mild depression, etc.

Synonyms: malaise, bombast, bosh, bunkum, claptrap, eyewash, fustian, hooey

verb

1. To utter idle, meaningless talk.

adjective

1. Dull; uninteresting; insipid.

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

2. Low in spirit or health; down.

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

interjection

1. An expression of mild frustration.

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

2. (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!”

3. Representing the sound of vomiting.

Synonyms: yada yada yada, bleah, bleh