noun

• (chiefly military) The use of gunpowder-type weapons, mainly cannon, as opposed to swords or bayonets.
  "Killing people became much easier and faster once armies started using gunfire."
• (military) The time of firing of the morning gun or the evening gun.
  "Art. 33. All Plying boats, with the exception of two which are to be weekly appoin[t]ed by the Chief Commissary of Police and Harbour Master, and at gunfire in the evening to be placed in a tier alongside of the Quay or at a place to be pointed out by these Officers and fastened by a claim and a padlock, the key of which is to be kept by the Porter on duty or by the Police Guard who is to release them at gunfire in the morning."
• (military slang) Tea, a cup of tea, especially one served early in the morning before first parade.
  "They had only in them the rolled mattresses, the neatly piled bed-boards and the empty tea-buckets of the orderly-men, empied of their last gun-fire."