macrocephalic Syllabification: (mac·ro·ce·phal·ic)Pronunciation: /ˌmakrōsəˈfalik/ (also macrocephalous /-ˈsefələs/)Definition of macrocephalic adjective Anatomy having an unusually large head. Derivatives macrocephalyPronunciation: /-ˈsefəlē/ noun macrocephalic in other Oxford dictionaries Definition of macrocephalic in the British & World English dictionary