The separation of intense emotion from its real object and its redirection toward someone or something that is less offensive or threatening in order to avoid dealing directly with what is frightening or threatening. The purpose of displacement is to avoid having to cope with the actual reality that is too painful. Instead, by using displacement, an individual is able to still experience his or her anger, but it is directed at a less threatening target than the real cause. In this way, the individual does not have to be responsible for the consequences of his/her anger and feels more safe.
Here is a textbook example of this defense mechanism.