Generous politician (7)
I believe the answer is:
This clue is a double definition.
'generous' is the first definition.
(similar in meaning)
'politician' is the second definition.
(I've seen this before)
(Other definitions for liberal that I've seen before include "Politically progressive" , "Favouring a political philosophy of progress and reform" , "Large-minded" , "enlightened" , "Not strict" .)