be all mouth

Related to be all mouth: dry mouth, Mouth ulcer

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.
See also: all, mouth
Farlex Dictionary of Idioms.

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.
See also: all, mouth
Farlex Partner Idioms Dictionary

be all ˈmouth

(British English also be all mouth and (no) ˈtrousers) (informal) if you say somebody is all mouth, you mean that they talk a lot about doing something, but are, in fact, not brave enough to do it: Don’t be scared of her. She won’t hurt you — she’s all mouth.
See also: all, mouth
Farlex Partner Idioms Dictionary
See also:
  • all piss and wind
  • all mouth and trousers
  • all mouth and no trousers
  • trouser
  • all talk and no trousers
  • big talk
  • great talkers are little doers
  • walk your talk
  • spout off
  • walk the talk