In the Name of God, the Compassionate, the Merciful.
Hi!
Conversation
A: What is money?
B: Money is something you exchange for something else.
A: What does exchange mean?
B: To exchange means … Let me show you.
What does exchange mean? ←
Is “exchange” a noun or a verb in this sentence?
Thank you
Verb
“Trade” would be a possible replacement here, but what B: is describing is more specifically using money to buy something. Trading money for some item.
There is a Latin phrase “quid pro quo” which means “something for something” meaning trading or buying something.
As a noun, “exchange” could refer to a place where things are traded such as a stock exchange where people buy and sell stocks or a money exchange.
It can also mean the trade itself.
“He traded a few beans for a cow. He came out really well in the exchange.”
Thank you so much, Arinker 
Very nice.
Exchange means replacement.
Suppose you have five pounds and you buy (paying that amount) a kilogram of apple at a shop. Here an exchange of things has taken place between you and the shopkeeper. Apples have replaced the money.
The word ‘exchange’ can be used as a noun and as a verb. Here, in your sentence, it is a noun.
Exchange can also be an adjective.
Exchange student
Exchange rate
Exchange, Trade and Swap have similar meanings, but they tend to be used in different contexts.
Thank you so much, Anglophile
Very nice.
Thank you so much, NearlyNapping
Very nice.
In this sentence, “exchange” is a verb. It means to give something and receive something in return.