中|なかnaka[1]atamadaka (head-high)

1. nouninside; interior
   彼かれは自分じぶんのお金かねを全部ぜんぶ箱ばこの中なかに入いれた。↗

   He put all his money in the box.
2. noun, adverbamong; within
   これらの商品しょうひんの中なかから１つ選えらびなさい。↗

   Choose one from among these products.
3. nounmiddle; center; centre
4. noun, adverbduring; while; middle; midst; amid
   身みを切きるような寒さむい中なかでわざわざ遊あそばなくてもいいじゃない。↗

   You don't have to play outside in the biting wind.
5. nouninterval; gap
6. nounmean; average
7. no-adjectivesecond (of three, e.g. sons, volumes); middle
8. no-adjectivemedium grade; medium quality
9. nounred-light district

• Synonym内部ないぶNeutralSino-Japanese word for the interior or inside, also of an organization as in 「内部の事情」; more formal than 「中」.
• SynonymうちNeutralCovers being inside or within a period of time, as in 「若いうちに」, and can mean one's own home; 「中」 is specifically about the inside of a space.
• Synonym内側うちがわNeutralThe inner side or face of something, or the area within a line as in 「線の内側」; stresses the contrast with the outside.
• SynonymミドルNeutralLoanword for middle, medium or middle-aged, as in 「ミドル級」; it never means the inside of something.
• Related真ん中まんなかNeutralThe exact middle or center point, as in 「部屋の真ん中」; 「中」 just means inside and need not be the center.
• Related中央ちゅうおうNeutralA central area, and also the central government or the capital, as in 「中央線」 and 「中央集権」; more formal than 「真ん中」.
• Related中心ちゅうしんNeutralA geometric center or the core of something, as in 「円の中心」 and 「話題の中心」; stresses being the central point or focus.
• Related中間ちゅうかんNeutralA position between two things, or a point partway through, as in 「駅と家の中間」 and 「中間試験」.
• Related真っ只中まっただなかNeutralThe very center, or the height of an intense situation as in 「嵐の真っ只中」; stresses being right in the thick of it.
• Related真中まなかWrittenAn older form of 「真ん中」 meaning the exact middle rather than the inside; rarely used today — say 「真ん中」 in everyday speech.
• Related正中せいちゅうWrittenWritten term for the exact center, also for a celestial body crossing the meridian; not used in everyday speech.
• Related中心点ちゅうしんてんWrittenThe single central point, used mostly in geometry or explanations; in ordinary contexts plain 「中心」 is the usual word.
• Related中点ちゅうてんWrittenThe midpoint of a line segment, or the 「・」 punctuation mark; a term from mathematics and typesetting, unrelated to the inside sense of 「中」.
• Related只中ただなかWrittenThe exact middle or the height of something; usually seen as 「真っ只中」, and on its own it reads as written style.
• Related内方ないほうWrittenArchaic word for the inside, also an honorific for another person's wife; almost never used today.
• RelatedインサイドNeutralLoanword for the inner side, used mostly in sports contexts such as 「インサイドキック」.
• Antonym外そとNeutralThe direct opposite of 「中」: the outside, or outdoors.
• AntonymほかNeutralOther people or things, or elsewhere, as in 「他の人」; not a strict opposite of the inside sense of 「中」, only contrasted with it in inside-outside comparisons.
• AntonymよそNeutralAnother place, someone else's home, or outside one's circle; more often paired against 「うち」, and only contrasts with 「中」 in inside-outside comparisons.

「中」 is the default for inside. Use 「真ん中」 for the exact middle, 「中心」 for the core, 「中間」 for between two things, 「内側」 for the inner side, 「内部」 for inside an organization; 「内」 also covers time periods. 「中央」 is more formal and can mean the central government. 「インサイド」 and 「ミドル」 suit sports and size or age talk. 「真中」「内方」 are dated, 「正中」「只中」 lean written, and 「中心点」「中点」 are geometry, explanation or typography terms. 「外」 is the true opposite; 「他」 and 「余所」 contrast with 「中」 only in inside-outside contexts.

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

1. 【なか】 物ものの内側うちがわ。
2. 【チュウ】 大おおきいとも小ちいさいとも言いえない状態じょうたい。
3. 【チュウ】 成績評価せいせきひょうかにおいて、優すぐれているとも劣おとっているとも言いえない状態じょうたい。平均的へいきんてき。
4. 【チュウ】 大規模だいきぼな文章ぶんしょうや書籍しょせきなどで、中なかの方ほうの部分ぶぶん。
5. 【チュウ】 動作どうさや行為こういのただなかにあること。また語彙ごいにより、行為こうい発生はっせい後ごの状態じょうたいの継続けいぞくやなんらかの行為こういのための準備じゅんび期間きかんにあることなども表あらわす。
6. 【チュウ】 その範囲はんいのなか。
7. 【チュウ】 （「A中ちゅうのA」の形かたちで）その範囲はんいのなかで特とくにすぐれたもの、特異とくいなもの。
8. 【ジュウ・チュウ】 それが終おわるまでのいつか。