Possess new shelter (5)
I believe the answer is:
haven
'shelter' is the definition.
(I know that haven is a type of shelter)
'possess new' is the wordplay.
'possess' becomes 'have' (synonyms).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'have'+'n'='HAVEN'
(Other definitions for haven that I've seen before include "Place of safety or sanctuary" , "Place of shelter" , "Safe harbour" , "Small port, refuge" , "Sheltered port" .)