Money fool rejected (3)
I believe the answer is:
tin
'money' is the definition.
(I've seen this before)
'fool rejected' is the wordplay.
'fool' becomes 'nit' (I've seen this before).
'rejected' is a reversal indicator.
'nit' back-to-front is 'TIN'.
(Other definitions for tin that I've seen before include "Metal in Argentina" , "loaf of bread" , "Silvery metallic element" , "Cornish metal?" , "Silvery-white metal used in cans" .)