Exchanges

noun

1. An act of exchanging or trading.

   "All in all, it was an even exchange."

2. A place for conducting trading.

   "The stock exchange is open for trading."

3. A telephone exchange.
4. The fourth through sixth digits of a ten-digit phone number (the first three before the introduction of area codes).

   "NPA-NXX-1234 is standard format, where NPA is the area code and NXX is the exchange."

5. A conversation.

   "After an exchange with the manager, we were no wiser."