The Collaborative International Dictionary
                    Macrencephalous
                    
                        
                
                                                                    Macrencephalic \Mac`ren*ce*phal"ic\, Macrencephalous \Mac`ren*ceph"a*lous\, a. [Macro + encephalic, encephalous.] Of or pertaining to macrencephaly; having a large brain.
Wiktionary
                    macrencephalous
                    
                        
                
                                                                    a. macrencephalic
WordNet
                    macrencephalous
                    
                        
                
                                                                    adj. having a large brain case [syn: macrencephalic]