Old house, ancestral, ruined (9)
I believe the answer is:
lancaster
'old house' is the definition.
(I've seen this before)
'ancestral ruined' is the wordplay.
'ruined' is an anagram indicator.
'ancestral' is an anagram of 'LANCASTER'.
(Other definitions for lancaster that I've seen before include "Fifteenth century house" , "He appeared in many films" , "Say Crouchback" , "historic city" , "9 [HOUSE]" .)