More impecunious (6)
I believe the answer is:
poorer
'more impecunious' is the definition.
('poor' can be similar in meaning to 'impecunious')
This is all the clue.
(Other definitions for poorer that I've seen before include "Less rich" , "More impecunious" , "Less well-off" , "'Having less money, fewer possessions (6)'" .)