Destroys a cursed expedition (7)
I believe the answer is:
crusade
'expedition' is the definition.
(Crusade is an example)
'destroys a cursed' is the wordplay.
'destroys' indicates anagramming the letters (I've seen 'destroyed' mean this).
'a'+'cursed'='acursed'
'acursed' is an anagram of 'CRUSADE'.
(Other definitions for crusade that I've seen before include "Advertising campaign" , "religious campaign" , "Used car involved in campaign for a cause" , "Medieval Christian military expedition to capture the Holy Land" , "Vigorous campaign" .)