trench mortar trench mortar /trɛntʃ ˈmɔːrtər/

noun

1. A muzzle-loading high-angle gun with a short barrel that fires shells at high elevations for a short range  ( howitzer , trench mortar , mortar )
   a muzzle-loading high-angle gun with a short barrel that fires shells at high elevations for a short range
    The soldiers loaded the mortar, preparing for the oncoming assault.
   The soldiers loaded the mortar, preparing for the oncoming assault.