How to say "brain" in Japanese

Choosing the right word

脳のうJLPT N1approx.Common
nounThe word for the brain as a physical organ; it is the neutral term, used by doctors and scientists and in ordinary conversation — for example, when discussing a head injury or how memory works.
その男おとこは自分じぶんの脳のうを撃ち抜うちぬいた。↗
The man blew out his own brains.
ブレーンCommon
nounA loanword that can refer to the organ, but 脳 is the word you want there; this one usually means 'the brains' — a person supplying ideas and advice behind a leader or project.

Use 脳 for the brain as an organ, in medical, scientific, or everyday contexts; 「ブレーン」 is a loanword that is seldom used for the organ and usually means 'the brains' — a person supplying ideas behind a leader or project.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

Japanese equivalents

脳のうbrain
脳髄のうずいbrain
ブレーンbrain (organ)

JLPT vocabulary levels are community estimates, not official (no official lists have been published since the 2010 revision).

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