In psychology, displacement (German: Verschiebung, lit. 'shift, move') is an unconscious defence mechanism whereby the mind substitutes either a new aim or a new object for things felt in their original form to be dangerous or unacceptable.
Example:
If your boss criticizes you at work, you might feel angry but can't express it directly to your boss. Instead, when you get home, you take out your frustration by yelling at a family member or slamming a door. Here, the family member or the door is a safer target for your anger than your boss. [1]