名詞 brain:

1. that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
   同義詞：encephalon
2. mental ability
   同義詞：brainpower, learning ability, mental capacity, mentality, wit
3. that which is responsible for one's thoughts and feelings; the seat of the faculty of reason
   同義詞：mind, head, psyche, nous
4. someone who has exceptional intellectual ability and originality
   同義詞：genius, mastermind, brainiac, Einstein
5. the brain of certain animals used as meat

動詞 brain:

1. hit on the head
2. kill by smashing someone's skull

1. He is one of the leading brains in the country.
   他是國家的知識分子精英。
2. I've had this tune on the brain all day but I can't remember what it's called.
   我腦海里整天回蕩著這個曲調(diào)，但我想不起來叫什麼了。
3. Brains are more than just education.
   有頭腦不僅指受過教育。
4. She has a good brain.
   她很有頭腦。

brain

n.（名詞）

The portion of the vertebrate central nervous system that is enclosed within the cranium, continuous with the spinal cord, and composed of gray matter and white matter. It is the primary center for the regulation and control of bodily activities, receiving and interpreting sensory impulses, and transmitting information to the muscles and body organs. It is also the seat of consciousness, thought, memory, and emotion.
大腦：脊椎動物中樞神經(jīng)系統(tǒng)的一個組成部分，為頭蓋骨包住，與脊椎相連，由灰質(zhì)與白質(zhì)組成，是調(diào)節(jié)和控制身體運動，接收和解釋感覺沖動，向肌肉和身體器官發(fā)送信息的基本中心，也是意識，思想，忘記和情感的活動中心
A functionally similar portion of the invertebrate nervous system.
腦：無脊椎動物神經(jīng)系統(tǒng)中具有類似功能的部分

Intellectual ability; mind:
智力；智能：
例句：
a dull brain; a quick brain.
笨腦瓜；快腦瓜

Often brains Intellectual power; intelligence:
常作 brains 智力；理解力：
例句：
brains and good looks.See Synonyms at mind
理解力和好眼光參見 mind

A highly intelligent person.
高智力的人
Often brains The primary director or planner, as of an organization or movement.
常作 brains 首腦：組織或運動的主要領(lǐng)導(dǎo)人或策劃者
The control center, as of a ship, aircraft, or spacecraft.
控制中心：船、飛機或宇宙飛船的控制中心
v.tr.（及物動詞）
brained,brain.ing,brains 【俚語】
To smash in the skull of.
打破…的腦袋
To hit on the head.
打…的頭部

<習(xí)慣用語>beat (one`s) brains (out)
Informal To exert or expend great mental effort:
【非正式用語】 絞盡腦汁，大費腦筋：用光或耗盡極大的智力努力：
例句：
She beat her brains out during the examination.
在考試中她絞盡腦汁

on the brain
Obsessively in mind:
熱衷于，念念不忘：一心想著某事：
例句：
The coach has winning on the brain.
教練一心想著取得勝利

pick (someone`s) brain 或
pick (someone`s) brains
To explore another`s ideas through questioning.
思想剽竊：在解決問題中使用別人的想法
rack (one`s) brain【非正式用語】
To think long and hard:
冥思苦想：長時間艱苦地思考：
例句：
I racked my brain for hours trying to recall her name.
幾小時來我苦苦思索以期回想起她的名字

來源：
Middle English
中古英語
from Old English brôgen
源自 古英語 brôgen