Atrocious house in ruins (7)
I believe the answer is:
heinous
'atrocious' is the definition.
(synonyms)
'house in ruins' is the wordplay.
'ruins' indicates an anagram.
'house'+'in'='housein'
'housein' with letters rearranged gives 'HEINOUS'.
(Other definitions for heinous that I've seen before include "Very wicked, maybe in-house" , "Utterly odious (crime)" , "Diabolic" , "Execrable" , "Shocking (offence)" .)