The Collaborative International Dictionary of English v.0.48:
Encephalocele \En*ceph"a*lo*cele\, n. [Gr. 'egke`falos the brain + kh`lh tumor.] (Med.) Hernia of the brain. [1913 Webster]WordNet (r) 3.0 (2006):
encephalocele n 1: protrusion of brain tissue through a congenital fissure in the skull