/blɑ:; blɑ/
n [U] (infml 口) talk that sounds impressive but actually says very little 冠冕堂皇的废话
*That's just a lot of blah. 那纯粹都是胡扯.
* There he goes, blah blah blah, talking nonsense as usual. 他又来这一套了, 夸夸其谈, 像往常一样谈来谈去都是废话.