Launder western money initially neglected (4)
I believe the answer is:
wash
'launder' is the definition.
(washing is a kind of laundering)
'western money initially neglected' is the wordplay.
'western' becomes 'w'.
'money' becomes 'cash' (I've seen this before).
'initially neglected' means to remove the first letter.
'cash' with its initial letter removed is 'ash'.
'w'+'ash'='WASH'
(Other definitions for wash that I've seen before include "put on thin coat" , "Brush with ink; launder" , "Be credible" , "Stand up" , "Cancelled event - utter failure" .)