1. the thwarting of impulses or actions that prevents individuals from obtaining something they have been led to expect based on past experience, as when a hungry animal is prevented from obtaining food that it can see or smell or when a child is prevented from playing with a visible toy. Internal forces can include motivational conflicts and inhibitions; external forces can include the actions of other individuals, admonitions of parents or others, and the rules of society.

2. the emotional state an individual experiences when such thwarting occurs.

3. in classical psychoanalytic theory, the damming up of psychic energy, which then seeks an outlet in wish-fulfilling fantasies and dreams or in various neurotic symptoms. —frustrate vb.