Animal skin not in hole (7)
I believe the answer is:
hideout
'hole' is the definition.
(thesaurus)
'animal skin not in' is the wordplay.
'animal skin' becomes 'hide' (hide is a kind of animal skin).
'not in' becomes 'out' ('out' is the opposite to 'in').
'hide'+'out'='HIDEOUT'
(Other definitions for hideout that I've seen before include "Place to lie low" , "den" , "retreat" , "sanctuary" .)