Refers to the very top or crown of the head. Often used in contexts like striking the top of the head or describing a bald spot.
I fell and hit the top of my head hard.
He is bald on the crown of his head.
Standard kanji spelling.
Contains outdated kanji; rarely used.
Compound of 脳 (brain) and 天 (top/heaven), literally 'brain top'. The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning.