all mouth and trousers

Etymology
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.

Adjective

 * 1)  Superficial, engaging in empty, boastful talk, but not of real substance.

Translations

 * Catalan: molt soroll i poques nous
 * Finnish: ei suuret sanat suuta halkaise
 * French: que de la gueule, rien dans le pantalon
 * German: große Klappe, nichts dahinter
 * Italian: tutto fumo e niente arrosto
 * Russian:, пуста́я бо́чка гро́мче греми́т