A defence mechanism is an unconscious psychological mechanism that reduces anxiety arising from unacceptable or potentially harmful stimuli.
Definition from Wikipedia – Defence mechanisms
Sigmund Freud ( FROYD; German: [ˈziːkmʊnt ˈfʁɔʏt]; born Sigismund Schlomo Freud; 6 May 1856 – 23 September 1939) was an Austrian neurologist and the founder of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst.
Definition from Wikipedia – Sigmund Freud
Anna Freud (3 December 1895 – 9 October 1982) was an Austrian-British psychoanalyst. She was the sixth and youngest child of Sigmund Freud and Martha Bernays.
Definition from Wikipedia – Anna Freud