Refers to the bony structure of the head. Less common in everyday conversation than 頭蓋骨 (ずがいこつ), but used in medical or anatomical contexts.
Learn the structure of the skull using a model.
kanji "person" radical at top
Refers to the kanji radical ⺅ (人) when it appears at the top of a character, as in 今 or 令. Used in discussions of kanji composition.
See also: 人屋根
The top part of '今' is called 人頭 (the 'person' radical at top).