Economic collapse wiping out Republican money (4)
I believe the answer is:
cash
'money' is the definition.
(cash is a type of money)
'economic collapse wiping out republican' is the wordplay.
'economic collapse' becomes 'crash' (financial crash).
'wiping out' indicates named letters should be taken away.
'republican' becomes 'R' (political abbreviation).
'crash' with 'r' removed is 'CASH'.
(Other definitions for cash that I've seen before include ""Readies"" , "bread" , "Money in the form of notes and coins" , "Brass" , "Hard currency" .)