1910, used at first in a general way for "sexual," from name of Sigmund Freud (1856-1939), Austrian psychiatrist. Freudian slip first attested 1959.
Freudian Freud·i·an (froi'dē-ən)
adj.
Relating to or being in accordance with the psychoanalytic theories of Sigmund Freud. n.
An individual who accepts the tenets of psychoanalytic theories of Sigmund Freud, especially a psychiatrist who applies Freudian theory and method in conducting psychotherapy.