Freudian definition of Lapsus
Lapsus is a verbal or written or memory error that appears as an unconscious manifestation.
Freud coined this term and listed possible forms of lapsus in his book Psychopathology of Daily Life.
According to Freudian philosophy, unacceptable thoughts or beliefs are repressed by conscience and slip-ups are the release of these latent contents. Thus, if dreams are the manifestation of unconscious contents in the sleeping patient, the slip is its counterpart in the awake patient.
The term is used today in a humorous manner when a person makes a verbal error, thus pointing to a hidden emotion in the speaker.