Missile disturbing poor Ted (7)
I believe the answer is:
torpedo
'missile' is the definition.
(missile from a submarine)
'disturbing poor ted' is the wordplay.
'disturbing' indicates an anagram (I've seen this in other clues).
'poor'+'ted'='poorted'
'poorted' is an anagram of 'TORPEDO'.
(Other definitions for torpedo that I've seen before include "Naval missile" , "Underwater bomb" , "Submarine weaponry" , "Destroy" , "Self-propelled marine weapon" .)