exchange

An act of exchanging or trading.

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

A place for conducting trading.

"The stock exchange is open for trading."

A telephone exchange.

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."

To trade or barter.

"I'll gladly exchange my place for yours."

To replace with, as a substitute.

"I'd like to exchange this shirt for one in a larger size."