头脑
tóunǎo · HSK 3
brain
🧠 头 (head) + 脑 (brain) = the head-brain, i.e. one's mind or a leader
头脑 literally stacks 头 'head' and 脑 'brain'. Together they name the thinking apparatus — hence both the literal 'head/noggin' sense and the figurative 'mind' or 'leader/brains of the outfit' sense.
头 — 页 (head/page) + 豆 (bean, phonetic)
The traditional form 頭 combines 頁 (xié), meaning 'head', with 豆 (dòu) as the phonetic component. 頁 itself originally depicted a person with an emphasized head. The simplified form 头 is a modern shorthand that replaces 豆+頁 with a simpler shape while keeping the same meaning of 'head' or 'top'.