The money Charlie has changed (4)
I believe the answer is:
cash
'the money' is the definition.
(cash is a type of money)
'charlie has changed' is the wordplay.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'changed' indicates anagramming the letters.
'has' is an anagram of 'ash'.
'c'+'ash'='CASH'
(Other definitions for cash that I've seen before include "Singer Johnny, d. 2003" , "Spondulicks" , "Funds" , ""Readies"" , "bread" .)