I. ˈblä noun
Etymology: imitative
Date: 1918
1. also blah-blah -ˌblä : silly or pretentious chatter or nonsense
2. plural
[perhaps influenced in meaning by blasé ]
: a feeling of boredom, lethargy, or general dissatisfaction
II. adjective
Date: 1922
: lacking interest : mediocre , boring
a blah winter day