I. blah 1 /blɑː/ BrE AmE noun
[ Date: 1900-2000 ; Origin: From the sound of empty talk ]
1 . blah, blah, blah spoken used when you do not need to complete what you are saying because it is boring or because the person you are talking to already knows it:
You know how Michelle talks: ‘Tommy did this, and Jesse did that, blah, blah, blah.’
2 . [uncountable] British English spoken remarks or statements that are boring and do not mean much:
the usual blah about everyone working harder
3 . the blahs [plural] American English informal a feeling of being sad and bored:
a case of the winter blahs
II. blah 2 BrE AmE adjective American English spoken informal
1 . not having an interesting taste, appearance, character etc:
The chili was kind of blah.
2 . slightly ill or unhappy:
I feel really blah today.