The Collaborative International Dictionary of English v.0.48:

Psychoanalysis \Psy`cho*a*nal"y*sis\, n.
   1. A method or process of psychotherapeutic analysis and
      treatment pf psychoneuroses, based on the work of Dr.
      Sigmund Freud (1856- 1939) of Vienna. The method rests
      upon the theory that neurosis is characteristically due to
      repression of desires consciously rejected but
      subconsciously persistent; it consists in a close analysis
      of the patient's mental history, effort being made to
      bring unconsciuos and preconscious material to
      consciousness; the methods include analysis of
      transferance and resistance. In some variants, stress is
      laid upon the dream life, and of treatment by means of
      suggestion.
      [Webster 1913 Suppl. +PJC]

   2. The theory of human psychology which is the foundation for
      the psychoanalytic therapy, which explores the relation
      between conscious and unconscious mental processes in
      motivating human behavior and causing neuroses.
      [PJC]

   3. An integrated set of theories of human personality
      development, motivation, and behavior based on a body of
      observations. --[Stedman]
      [PJC]

   4. One of several schools of psychotherapy, such as jungian
      psychoanalysis or freudian psychoanalysis. --[Stedman]
      [PJC] -- Psy`cho*an`a*lyt"ic, a.; Psych`o*an"al*ist,
      n., etc.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

psychoanalysis
    n 1: a set of techniques for exploring underlying motives and a
         method of treating various mental disorders; based on the
         theories of Sigmund Freud; "his physician recommended
         psychoanalysis" [syn: psychoanalysis, analysis, depth
         psychology]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "psychoanalysis":
   Adlerian psychology, Freudian psychology, Freudianism,
   Gestalt psychology, Horneyan psychology, Jungian psychology,
   Pavlovian psychology, Reichian psychology, Skinnerian psychology,
   Watsonian psychology, analysis, analytical psychology,
   apperceptionism, association psychology, associationism,
   behaviorism, behavioristic psychology, configurationism,
   depth interview, depth psychology, dianetics, dream analysis,
   dream symbolism, group analysis, interpretation of dreams,
   mental chemistry, metapsychology, orgone theory, psychanalysis,
   psychoanalytic method, psychoanalytic theory,
   psychoanalytic therapy, psychognosis, psychognosy,
   psychology of depths, stimulus-response psychology, structuralism,
   the couch