blah

Used to indicate boredom, indifference, or that something is uninteresting.

"He kept talking about his holiday, blah, blah, blah."

Unimportant talk, nonsense, or something dull and uninspiring.

"Don't listen to all that blah."

Feeling uninspired, dull, or generally lacking energy or enthusiasm.

"I'm feeling a bit blah today."