脳（のう、nou）
- brain

The Japanese word 脳 (のう) primarily means "brain." It refers to the organ located inside the skull that controls bodily functions and mental processes. It can also refer to the mental capacity or intelligence of a person. In medical contexts, it's used to discuss the anatomy and physiology of the brain and its various parts.

⚫︎人間の脳は複雑です。 Translation: The human brain is complex. ⚫︎彼は脳の病気にかかりました。 Translation: He has a brain disease. ⚫︎その問題について、脳を絞って考えました。 Translation: I racked my brains about that problem.

This word is used in various contexts. ⚫︎ When discussing the physical organ. ⚫︎ When talking about intelligence, thinking, or mental processes. ⚫︎ In medical or scientific discussions related to the brain. It is a common and essential word in the Japanese language.

⚫︎ The standard way to write 脳 is with the kanji. ⚫︎ The reading (pronunciation) is always のう in hiragana. ⚫︎ There are no other common ways to write this word. ⚫︎ There is no variation in okurigana.

While there aren't direct synonyms in the same way as in English, related terms include: ⚫︎ 頭脳 (ずのう): Brain, intellect, mind, head. Often used to emphasize intelligence. ⚫︎ 頭 (あたま): Head; can sometimes refer to the brain in a more casual way.

There aren't specific antonyms in the same sense, but words relating to lack of intelligence or mental function can be seen as opposites in a figurative sense: ⚫︎ 愚か (おろか): Foolish, stupid. ⚫︎ 無能 (むのう): Incompetent, incapable.

彼の脳は非常に発達している。 ・Translation: His brain is very developed. ・Explanation: This sentence describes someone with a high level of intelligence or mental capacity. It emphasizes the function of the 脳.

事故で脳に損傷を受けた。 ・Translation: He suffered brain damage in the accident. ・Explanation: This sentence deals with a medical context, highlighting a physical injury to the 脳.

The kanji 脳 is a combination of two parts: ⚫︎ The radical 月 (getsuzuki, meaning "moon" or "flesh") which is also used for body parts. ⚫︎ The phonetic component 㥮 (nou, which indicates the sound). The word's etymology reflects its meaning as a part of the human body and its function as the center of thinking.