Horse place is not readily changing (6)
I believe the answer is:
stable
'horse place' is the definition.
'stable' can be an answer for 'place' (I have seen 'Place of birth' mean 'stable' so perhaps 'place' could also mean 'stable'). I'm not sure about the 'horse' bit.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for stable that I've seen before include "Permanent" , "It might accommodate Arab" , "Home for horses" , "Firmly-fixed; building" , "Steadfast, resolute" .)