The Collaborative International Dictionary of English v.0.48:

Psyche \Psy"che\, n. [L., fr. Gr. PSychh` Psyche, fr. psychh`
   the soul.]
   1. (Class Myth.) A lovely maiden, daughter of a king and
      mistress of Eros, or Cupid. She is regarded as the
      personification of the soul.
      [1913 Webster]

   2. The soul; the vital principle; the mind.
      [1913 Webster]

   3. [F. psych['e].] A cheval glass.
      [1913 Webster]

WordNet (r) 3.0 (2006):

psyche
    n 1: that which is responsible for one's thoughts and feelings;
         the seat of the faculty of reason; "his mind wandered"; "I
         couldn't get his words out of my head" [syn: mind,
         head, brain, psyche, nous]
    2: the immaterial part of a person; the actuating cause of an
       individual life [syn: soul, psyche]
    3: (Greek mythology) a beautiful princess loved by Cupid who
       visited her at night and told her she must not try to see
       him; became the personification of the soul

Moby Thesaurus II by Grady Ward, 1.0:

87 Moby Thesaurus words for "psyche":
   Vernunft, anima, anima humana, animus, atman, ba, brain, brains,
   breath, breath of life, buddhi, coconscious,
   collective unconscious, conception, conscience, conscious self,
   death instinct, discourse of reason, discursive reason,
   divine breath, divine spark, ego, ego ideal, ego-id conflict,
   elan vital, esprit, ethical self, foreconscious, gray matter, head,
   headpiece, heart, id, inner man, intellect, intellection,
   intellectual faculty, intelligence, jiva, jivatma, khu,
   libidinal energy, libido, manes, mens, mental capacity, mentality,
   mind, motive force, nephesh, nous, persona, personality,
   pleasure principle, pneuma, power of reason, preconscious,
   primitive self, psychic apparatus, purusha, racial unconscious,
   ratio, rationality, reason, reasoning, reasoning faculty, ruach,
   self, shade, shadow, smarts, soul, spirit, spiritual being,
   spiritus, subconscious, subconscious mind, subliminal,
   subliminal self, submerged mind, superego, the self, unconscious,
   unconscious mind, understanding, vital force, vital impulse