Fur coat material encloses family (8)
I believe the answer is:
sealskin
'fur coat' is the definition.
'encloses family' is the wordplay.
'encloses' becomes 'seals' (I can't justify this - if you can you should believe this answer much more).
'family' becomes 'kin' (synonyms).
'seals'+'kin'='SEALSKIN'
'material' is the link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for sealskin that I've seen before include "Fur - lean kiss (anag)" , "Fur from the sea" , "Form of fur for garments" , "Marine fur" , "prepared fur" .)