Determined to include fur
I believe the answer is:
ermine
'fur' is the definition.
(I know that ermine is a type of fur)
'determined to include' is the wordplay.
'to include' says the answer is hidden in the clue.
'ERMINE' is hidden within 'determined'.
(Other definitions for ermine that I've seen before include "White-coated stoat" , "White fur associated with judges" , "garb for nobility" , "Winter fur of the stoat" , "Ceremonial fur" .)