to trade or exchange (something or someone) for another
something that is exchanged
(finance) Also called swap option, swaption. a contract in which the parties to it exchange liabilities on outstanding debts, often exchanging fixed interest-rate for floating-rate debts (debt swap), either as a means of managing debt or in trading (swap trading)
swapper, swopper, noun
C14 (in the sense: to shake hands on a bargain, strike): probably of imitative origin
c.1300, "to strike, strike the hands together," possibly imitative of the sound of hitting. The sense of "exchange, barter, trade" is first recorded 1594, possibly from the practice of slapping hands together as a sign of agreement in bargaining. The noun in this sense is attested from 1625.