ex·change 
(ĭks-chānj)
(ĭks-chānj)v. ex·changed, ex·chang·ing, ex·chang·es
v.tr.
1. To give in return for something received; trade: exchange dollars for francs; exchanging labor for room and board.
2. To give and receive reciprocally; interchange: exchange gifts; exchange ideas.
3. To give up for a substitute: exchange a position in the private sector for a post in government.
4. To turn in for replacement: exchange defective merchandise at a store.
v.intr.
1. To give something in return for something received; make an exchange.
2. To be received in exchange: At that time the British pound exchanged for $2.80.
n.
1. The act or an instance of exchanging: a prisoner exchange; an exchange of greetings.
2. One that is exchanged.
3. A place or network for exchanging things, especially a center where securities or commodities are bought and sold.
4. A telephone exchange.
5.
a. A system of payments using instruments, such as negotiable drafts, instead of money.
b. The fee or percentage charged for participating in such a system of payment.
6. A bill of exchange.
7. A rate of exchange.
8. The amount of difference in the actual value of two or more currencies or between values of the same currency at two or more places.
9. A dialogue: a heated exchange between the two in-laws.
adj.
Of or relating to a reciprocal arrangement between a local and a foreign institution or group: an exchange student; exchange programs for students learning foreign languages.
[Middle English eschaungen, from Anglo-Norman eschaungier, from Vulgar Latin *excambiāre : Latin ex-, ex- + Late Latin cambīre, to exchange, barter; see CHANGE.]
ex·changea·ble adj.