Trooped out to see a naval weapon (7)
I believe the answer is:
'a naval weapon' is the definition.
(missile used at sea)
'trooped out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'trooped' with letters rearranged gives 'TORPEDO'.
'to see' acts as a link.
(Other definitions for torpedo that I've seen before include "Self-propelled underwater explosive device" , "Naval missile" , "Self-propelled submarine weapon" , "Naval weapon" , "Underwater bomb" .)