Blah/blɑː/ Definition 1 of 3Pro Tip 1/3Expressing Impatience Use 'blah' when you're tired of what someone is saying or it seems unimportant. She went on about her diet, blah blah blah, so I tuned out. Pro Tip 2/3Mimicking Speech 'Blah' mimics the sound of speech when details don't matter or are too long. He started explaining the process, blah blah blah, so I got the gist. Pro Tip 3/3Summarizing Overload Use 'blah' to summarize a speech or writing that overloaded you with information. The lecture was an hour of legal terms, blah blah blah!