Brain
Intellect
noun
Your head brain is that thing in your noggin that you think with — your brain, in other words.
Compared to 脳, which is the physical brain, 頭脳 is about your intellect. It refers to your ability to think and strategize, like in the phrase 頭脳プレー (a clever, strategic move, whether in sports or everyday life).
This is a jukugo word, which usually means on'yomi readings from the kanji. You didn't learn 頭's on'yomi when you learned the kanji, so here's a mnemonic to help you:
You love to show off your smartypants brain at the zoo (ず). You refer to all the animals by their scientific names ("Orangutan? Ah, you must mean the Pongo Pygmaeus.") and recite obscure zoologic trivia to anyone who will listen. No one can doubt your intellect after a day at the zoo with you.
頭脳労働
mental labor
頭脳集団
brain trust
頭脳プレー
a strategic play
頭脳戦
battle of wits
頭脳派
intellectual type
頭脳を使う
to use one's brain
頭脳をフル回転させる
to use one's brain to the fullest
頭脳をきたえる
to train one's brain
頭脳を働かせる
to use one's brain
優秀な頭脳
a brilliant mind
シャープな頭脳
a sharp mind
多様な頭脳
diverse minds
彼は非常に優秀な頭脳の持ち主だ。
He has an exceedingly brilliant mind.
私は頭脳を使う仕事が好きなんです。
I like a job that requires me to think.
これは頭脳戦になりそうですね…。
This looks like it's going to be a battle of wits…
それは、世界最高の頭脳集団によって設計されたシステムだった。
It was a system designed by the world’s greatest minds.