Alteration for loose cash (6)
I believe the answer is:
change
I believe this clue is a double definition.
'alteration' is the first definition.
(I know that alteration can be written as change)
'loose cash' is the second definition.
(coins)
'for' is the link.
(Other definitions for change that I've seen before include "Transfer" , "Money returned as balance after purchase" , "Alteration" , "Mutate or transform" , "Word for small coins in pocket" .)