Exchange boggy area after losing a bit of money (4)
I believe the answer is:
swap
'exchange' is the definition.
(swapping is a kind of exchanging)
I cannot understand how the rest of the clue works.
(Other definitions for swap that I've seen before include "Exchange for paws" , "Exchange; hands back" , "Change over" , "Exchange goods" , "Fifty-fifty odds" .)