WordNet (r) 3.0 (2006):

Oedipus Rex
    n 1: (Greek mythology) a tragic king of Thebes who unknowingly
         killed his father Laius and married his mother Jocasta; the
         subject of the drama `Oedipus Rex' by Sophocles [syn:
         Oedipus, King Oedipus, Oedipus Rex]