all mouth and trousers

• all mouth and no trousers

From 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.

• Audio (AU)

  (file)

all mouth and trousers (not comparable)

1. (British, idiomatic) Superficial, engaging in empty, boastful talk, but not of real substance.

   Synonyms: (vulgar) all fart and no shit, all fart and no poo

• all hat and no cattle

• Michael Quinion (2004) “All mouth and trousers”, in Ballyhoo, Buckaroo, and Spuds: Ingenious Tales of Words and Their Origins, Washington, D.C.: Smithsonian Books in association with Penguin Books, →ISBN.