Found stable's jockey holding his heart on top of horse (9)
I believe the answer is:
establish
'found' is the definition.
(thesaurus)
'stable's jockey holding his heart on top of horse' is the subsidiary indication.
'jockey' is an anagram indicator (I've seen 'jockeys' mean this).
'holding his heart' becomes 'is' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'on top of' is a charade indicator (letters next to each other).
'horse' becomes 'h' ('H' can be a synonym of 'horse').
'stable' is an anagram of 'establ'.
'establ'+'is'+'h'='establish'
Can you help me to learn more?
(Other definitions for establish that I've seen before include "Create - lodge" , "Show to be true in his stable" , "Found or authenticate" , "Found - his stable (anag)" , "Verify" .)