Advance takings falling short (7)
I believe the answer is:
proceed
'advance' is the definition.
(I've seen this before)
'takings falling short' is the wordplay.
'takings' becomes 'proceeds' ('proceeds' can be a synonym of 'takings').
'falling short' means to remove the last letter.
'proceeds' with its last letter taken off is 'PROCEED'.
(Other definitions for proceed that I've seen before include "Go forward" , "'Continue, move ahead (7)'" , "Follow a certain course" , "Move forward" , "Continue, go ahead" .)