Type of fruit fool containing raisins originally (5)
I believe the answer is:
drupe
'type of fruit' is the definition.
'fool containing raisins originally' is the wordplay.
'fool' becomes 'dupe' ('dupe' can be a synonym of 'fool'**).
'containing' is an insertion indicator.
'originally' says to take the initial letters.
The first letter of 'raisins' is 'r'.
'dupe' placed around 'r' is 'DRUPE'.
(Other definitions for drupe that I've seen before include "Fruit with single stone" , "Fruit with a single seed" .)