Ancient city not completely destroyed? (4)
I believe the answer is:
troy
'ancient city' is the definition.
(Troy was an ancient city)
'not completely destroyed?' is the wordplay.
'not completely' says the answer is hidden in the clue.
'TROY' is hidden in the letters of 'destroyed'.
(Other definitions for troy that I've seen before include "System of weights; ancient city in Turkey" , "City of Paris" , "System of weights used for precious metals" , "part of Asia Minor" , "Where beautiful Helen came from" .)