Spendthrifts don't go to the rescue (4)
I believe the answer is:
save
'the rescue' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for save that I've seen before include "Rescue or salt away" , "Rescue from danger" , "Rescue for a rainy day?" , "Apart from" , "Preserve; except" .)