In ruins (8)
I believe the answer is:
derelict
'in ruins' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for derelict that I've seen before include "Fallen into ruin" , "Deserted and dilapidated" , "Abandoned, neglected" , "Abandoned and falling into ruin" , "Left to fall into ruin like abandoned house" .)