macrocephalous

adjective
mac·​ro·​ceph·​a·​lous | \ ˌmak-rō-ˈsef-ə-ləs How to pronounce macrocephalous (audio) \
variants: or macrocephalic \ -​sə-​ˈfal-​ik How to pronounce macrocephalic (audio) \

Medical Definition of macrocephalous

: having or being an exceptionally large head or cranium