USS Reliant weapons pod
A weapons pod was an exterior module that housed torpedo launchers on the aft roll bar of certain arrangements of Miranda-class starships, including the USS Reliant.
In 2285 during the Battle of the Mutara Nebula, the USS Enterprise landed a decisive blow to the Reliant, destroying its weapons pod. (Star Trek II: The Wrath of Khan)
The weapons pod was not named on screen, but identified in the script of Star Trek II: The Wrath of Khan. [1]