Confusion about large fortune (4)
I believe the answer is:
pile
'fortune' is the definition.
(I've seen this before)
'confusion about large' is the wordplay.
'confusion' becomes 'pie' (I've seen this in other clues).
'about' means one lot of letters goes inside another.
'large' becomes 'L' (eg in clothes sizes).
'pie' enclosing 'l' is 'PILE'.
(Other definitions for pile that I've seen before include "Fortune" , "A heap or stack" , "Post" , "large building" , "large amount of money" .)