skull 
/ˈskʌl/ noun
plural skulls /ˈskʌl/ noun [count] : the structure of bones that form the head and face of a person or animal
▪ He had a fractured skull. ▪ (informal) You need to get it into/through your thick skull [=you need to realize/understand] that you can't just sit there and expect everyone else to do your work for you! ▪ (informal) He can't seem to get it through his skull that I don't like him. — see picture at human
▪ He had a fractured skull. ▪ (informal) You need to get it into/through your thick skull [=you need to realize/understand] that you can't just sit there and expect everyone else to do your work for you! ▪ (informal) He can't seem to get it through his skull that I don't like him. — see picture at human
