From The Collaborative International Dictionary of English v.0.48 :
braincase \brain"case\ n.
the part of the skull that encloses the brain.
Syn: cranium, brainpan.
[WordNet 1.5]
From WordNet (r) 3.0 (2006) :
braincase
n 1: the part of the skull that encloses the brain [syn:
cranium, braincase, brainpan]