Found his stable ruined (9)
I believe the answer is:
establish
'found' is the definition.
(thesaurus)
'his stable ruined' is the wordplay.
'ruined' indicates an anagram.
'his'+'stable'='hisstable'
'hisstable' with letters rearranged gives 'ESTABLISH'.
(Other definitions for establish that I've seen before include "Found - institute" , "Found or authenticate" , "Found - his stable (anag)" , "Verify" , "Set up or found" .)