boring, predictable, or nonsensical talk or writing
Origin:
echoic
interjection
used, usually repeated one or more times, to suggest such talk or writing, esp. when it continues for a long time: and the speaker went on, blah, blah, blah, seemingly forever
adjective
feeling or being dull and lifeless
See blah in American Heritage Dictionary 4
noun
Worthless nonsense; drivel.
blahs A general feeling of discomfort, dissatisfaction, or depression: “Monday morning Oscar woke up with the blahs”(New Yorker).
adjective
Dull and uninteresting.
Low in spirit or health; down: sat around all day feeling blah.