Source : Webster's Revised Unabridged Dictionary (1913)

Sphinx \Sphinx\, n. [L., from Gr. sfi`gx, usually derived from
   sfi`ggein to bind tight or together, as if the Throttler.]
   1.
      (a) In Egyptian art, an image of granite or porphyry,
          having a human head, or the head of a ram or of a
          hawk, upon the wingless body of a lion.

Source : WordNet®

sphinx
     n 1: an inscrutable person who keeps his thoughts and intentions
          secret
     2: (Greek mythology) a riddling winged monster with a woman's
        head and breast on a lion's body; daughter of Typhon
     3: one of a number of large stone statues with the body of a
        lion and the head of a man that were built by the ancient
        Egyptians
     [also: {sphinges} (pl)]