Entrapment is the act of making someone commit a crime for the purpose of charging them with breaking the law in relation to that crime. Entrapment is a condition that must be perpetrated by law enforcement for it to be valid. If a person is found to have been entrapped, it is usual for the charges relating to that offense to be dropped.
In order for entrapment to be valid, the accuser must be able to show that they would not commit that crime under normal circumstances and only did so because someone induced them. An example of this would be if an under cover police officer asked a person to buy a drug for them who doesn't deal drugs and who had to go out of their normal course of actions to facilitate the crime.