To trade or barter.
To replace with, as a substitute.
To recommend and get recommendations.
The transfer of substances or elements like gas, amino-acids, ions etc. sometimes through a surface like a membrane.
The fourth through sixth digits of a ten-digit phone number (the first three before the introduction of area codes).
The loss of a minor piece (typically a bishop or knight) and associated capture of the more advantageous rook.
A telephone exchange.
A conversation.
An act of exchanging or trading.
The difference between the values of money in different places.
A place for conducting trading.
The loss of one piece and associated capture of another.