Pussy protecting old fur? (4)
I believe the answer is:
coat
'fur?' is the definition.
(an animal's coat)
'pussy protecting old' is the wordplay.
'pussy' becomes 'cat' (I've seen this in other clues).
'protecting' indicates putting letters inside (inserted letters are held or protected).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'cat' enclosing 'o' is 'COAT'.
(Other definitions for coat that I've seen before include "Outer garment" , "blanket" , "Warm outerwear" , "Outer covering" , "Overgarment" .)