Meaning : (economics) a market in which there are many buyers but only one seller.
Example :
A monopoly on silver.
When you have a monopoly you can ask any price you like.
Meaning : Exclusive control or possession of something.
Example :
They have no monopoly on intelligence.
Meaning : A board game in which players try to gain a monopoly on real estate as pieces advance around the board according to the throw of a die.