Destroyer destroyer (4)
'destroyer destroyer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mine that I've seen before include "Pit; explosive device" , "Pit; belonging to me" , "Coalpit" , "Donnybrook" , "Pit; source" .)
(Other definitions for u-boat that I've seen before include "Sea vessel" , "Take pool exercise" , "German World War One or World War Two submarine" , "About (anag)" , "Submersible warship of WWII" .)
'destroyer destroyer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for torpedo that I've seen before include "Trooped (anag.)" , "Trooped off with undersea missile" , "Submarine weaponry" , "Weapon travelling under water" , "To wreck" .)