brain

brain — noun

1. the soft organ in your skull that lets you think, remember, feel, and control mo

1.名詞A2
釋義

the soft organ in your skull that lets you think, remember, feel, and control movement.

例句

Doctors used a scan to check Mei's brain after the crash.

brain in a medical scan context

A hard fall from the bike caused swelling in Yusuf's brain.

同義詞
  • cerebrum

    technical and narrower; it can refer to only part of the brain.

  • grey matter

    informal and often used jokingly or figuratively.

  • mind

    usually means thoughts, not the physical organ itself.

用法筆記

Common with medical and body words such as 'scan', 'injury', 'tumor', and 'surgery'. Distinguish from sense 2: this sense names the physical organ, while sense 2 is about mental power.

2. mental strength for understanding things, learning fast, and working out problem

2.名詞C1
釋義

mental strength for understanding things, learning fast, and working out problems.

例句

Noa has the brains to solve the puzzle before anyone else.

have the brains to + verb

Use your brain and read the safety sign before touching the wire.

use your brain for practical thinking

同義詞
  • intelligence

    the most neutral formal noun for mental ability.

  • intellect

    slightly more formal and often stresses serious thinking.

  • smarts

    informal and common in everyday speech.

  • brainpower

    stresses mental effort used to solve a task.

反義詞
  • stupidity

    lack of good judgment or intelligence.

文法句型

have brains

use your brain

brain not muscle

用法筆記

Often appears in fixed expressions such as 'have brains' and 'use your brain'. Distinguish from sense 3: this sense is the quality itself, not a person who has it.

常見錯誤

❌Aiko is brains.
✅Aiko has brains.
💡bare 'brains' refers to intelligence, not directly to a person.
❌Use your brains before you cross the road.
✅Use your brain before you cross the road.
💡singular is more usual in this fixed instruction.

3. a person thought to be very smart, especially in study or technical work.

3.名詞C1
釋義

a person thought to be very smart, especially in study or technical work.

例句

Everyone called Ravi a brain after he fixed the school robot.

a brain = a very clever person

The company brought in two young brains to improve its phone app.

plural: brains for clever people

同義詞
  • genius

    stronger; suggests extremely high natural ability.

  • intellectual

    often used for someone interested in serious ideas and study.

  • egghead

    informal and can sound mocking.

  • whiz

    informal; often used for someone excellent in one area such as math or computers.

文法句型

be a brain

one of the brains

用法筆記

Often sounds slightly informal or teasing, and it is common in the plural for a group of very clever people. Distinguish from sense 4: a 'brain' here is simply a smart person, not necessarily the one leading a plan.

常見錯誤

❌Kenji is brain in our class.
✅Kenji is a brain in our class.
💡singular countable use needs 'a'.

4. the person in a team or scheme who thinks up the plan and directs how it is carr

4.名詞C1
釋義

the person in a team or scheme who thinks up the plan and directs how it is carried out.

例句

Police said Nadia was the brain behind the museum theft.

the brain behind + plan or crime

Although Sven spoke little, he was the brain of the whole campaign.

the brain of + group effort

同義詞
  • mastermind

    the closest match, especially for clever planning.

  • strategist

    stresses long-term planning rather than overall control.

  • organizer

    broader and more practical; not always the smartest person.

  • ringleader

    used mainly for the leader of a wrong or illegal group.

文法句型

the brain behind + noun

the brain of + group / operation

用法筆記

Most often used with 'behind' or 'of' when naming the project, operation, or crime. Distinguish from sense 3: this sense highlights control and planning, not just intelligence.

常見錯誤

❌Lior has the brain behind the plan.
✅Lior is the brain behind the plan.
💡this sense names the person responsible.
❌Mina was the brain for the robbery.
✅Mina was the brain behind the robbery.
💡'behind' is the usual preposition with this pattern.

brain — verb