be all mouth(redirected from is all mouth)
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be all mouth
To be full of boastful, arrogant, or shallow talk without the ability to deliver on such claims He talks a big game, but when it actually comes to asking out a woman, he's all mouth.
be all mouth (and no trousers)tend to talk boastfully without any intention of acting on your words. informal
1998 Oldie What was the point of the Sitwells?…The image was the point, transcending mere achievement…The Sitwells were all mouth and no trousers.