Meanings
mouth, meaning "talk" rather than action and trousers, presumably at the time of origin a reference to masculinity, either as trousers as a male item of clothing, or a reference to the genitals.
How to pronounce "all mouth and trousers":
AU
Superficial, engaging in empty, boastful talk, but not of real substance.
Example Sentences
1
He talks a big game but he's all mouth and trousers when it comes to actually doing the work.
2
Everyone thought he was a great leader, but he turned out to be all mouth and trousers.
3
The politician promised to solve all our problems, but he's just all mouth and trousers.
4
Don't listen to him, he's all mouth and trousers.
5
She acts confident but she's all mouth and trousers, she can't back it up.
