About hush money (4)
I believe the answer is:
cash
'money' is the definition.
(cash is a type of money)
'about hush' is the wordplay.
'about' becomes 'ca' (short for circa).
'hush' becomes 'sh'.
'ca'+'sh'='CASH'
(Other definitions for cash that I've seen before include "Ready money" , "Hard currency" , "Till" , "Money in the form of notes and coins" , ""Readies"" .)