The Collaborative International Dictionary of English v.0.48:

Omphalocele \Om"pha*lo*cele`\, n. [Gr. ? the navel + ? a tumor:
   cf. F. omphaloc['e]le.] (Med.)
   A hernia at the navel.
   [1913 Webster]

WordNet (r) 3.0 (2006):

omphalocele
    n 1: protrusion of the intestine and omentum through a hernia in
         the abdominal wall near the navel; usually self correcting
         after birth [syn: umbilical hernia, omphalocele]