Resolve — pay up (6)
I believe the answer is:
settle
I believe this clue is a double definition.
'resolve' is the first definition.
(I know that resolve can be written as settle)
'pay up' is the second definition.
(I've seen this before)
(Other definitions for settle that I've seen before include "Pay up or sink down" , "Make permanent home, stop wandering" , "near Giggleswick" , "Colonise with a seat" , "piece of furniture" .)