Alter; money (6)
I believe the answer is:
change
I believe this is a double definition.
'alter' is the first definition.
(I know that alter can be written as change)
'money' is the second definition.
(I know that change is a type of coin)
(Other definitions for change that I've seen before include "Alter, modify" , "Transfer" , "Coppers, perhaps" , "protean" , "Cash" .)