Swap or trade (8)
I believe the answer is:
exchange
I believe this clue is a double definition.
'swap' is the first definition.
(I've seen this before)
'trade' is the second definition.
(exchange of items)
(Other definitions for exchange that I've seen before include "place of business" , "Barter; switch" , "Fight -- angel chews box (anag)" , "'Swap, trade (8)'" , "Short conversation or argument" .)