Release money (4)
'release money' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bail that I've seen before include "Security for temporary release" , "In cricket, wooden cross-piece placed on stumps" , "Part of a wicket - legal payment" , "Cross piece on wicket" , "Partition in stable" .)
(Other definitions for ransom that I've seen before include "Kidnapper's demand" , "Money to get a hostage released" , "Buy freedom" , "delivery charge" , "money from reluctant donor" .)