House in reconstructed base (7)
I believe the answer is:
heinous
'base' is the definition.
(thesaurus)
'house in reconstructed' is the wordplay.
'reconstructed' is an anagram indicator.
'house'+'in'='housein'
'housein' is an anagram of 'HEINOUS'.
(Other definitions for heinous that I've seen before include "Utterly wicked" , "Extremely evil" , "Iniquitous" , "Wicked (offence)" , "Atrocious" .)