Trooped off to get a missile (7)
I believe the answer is:
torpedo
'a missile' is the definition.
(thesaurus)
'trooped off' is the wordplay.
'off' indicates an anagram.
'trooped' is an anagram of 'TORPEDO'.
'to get' is the link.
(Other definitions for torpedo that I've seen before include "American sandwich made with a long split roll" , "Missile fired from underwater submarine" , "Sea-borne missile" , "To wreck" , "[SOMETHING FISHY]" .)