骨髄|こつずいkotsuzui

1. noun, anatomybone marrow; medulla
2. nounheart's core; depths of one's heart
3. nounmain point; vital part

• Synonym核かくNeutralThe center or core of a thing, standing alone as in 「組織の核」「核となる」; also the atomic nucleus and nuclear weapons. 「骨髄」 leans figurative, the depths of the heart.
• Synonym眼目がんもくWrittenThe focal point or chief purpose, as in 「この計画の眼目」; written style. 「骨髄」 leans toward the depths of the heart.
• Synonym髄ずいNeutralMarrow or plant pith; mostly seen in set phrases such as 「骨の髄まで」. 「骨髄」 names the marrow tissue itself and also figuratively the very core of a thing.
• Related趣旨しゅしNeutralThe gist or intent of what one wants to convey, as in 「趣旨を説明する」; stresses the aim behind a statement, not the heart of a matter.
• Related骨子こっしNeutralThe skeleton or outline of a plan or bill, as in 「法案の骨子」; used for drafts and schemes rather than deep feelings.
• Related要領ようりょうNeutralThe essentials, as in 「要領を得ない」, and also the knack of doing something; not about marrow or the heart's core.
• Related要点ようてんNeutralThe main points, as in 「要点をまとめる」; the most general and versatile word for the gist of something.
• Related要旨ようしNeutralThe gist, as in 「論文の要旨」; typically the summary or abstract of a piece of writing.
• Related本質ほんしつNeutralThe essential nature of something, as in 「問題の本質」; stresses inherent properties rather than the innermost heart.
• Related中核ちゅうかくNeutralThe core or nucleus, as in 「中核をなす」; often used of organizations and groups.
• Related中枢ちゅうすうNeutralThe control center, as in 「神経中枢」「中枢機能」; emphasizes the seat of command or coordination.
• Related核心かくしんNeutralThe crux of a matter, as in 「核心に迫る」; stresses the vital point at issue.
• Related要項ようこうNeutralA list of required items or main points, as in 「募集要項」; typical of application and recruitment documents.
• RelatedかなめNeutralNative Japanese word for the linchpin, as in 「チームの要」; stresses what holds the whole together.
• Related基幹きかんNeutralThe backbone or mainstay, as in 「基幹産業」; used mainly of industries and systems.
• Related枢軸すうじくNeutralThe axis or pivot, as in 「枢軸国」; mostly in political and historical contexts.
• RelatedエッセンスNeutralLoanword for the essence or extract, as in 「エッセンスを抽出する」; also a flavoring essence.
• RelatedポイントNeutralLoanword for the point, as in 「ポイントを押さえる」; very common in speech.
• Related主意しゅいWrittenWritten prose and rather rare; the central meaning of a text. 「骨髄」 figuratively points to the depths of the heart or the root of a thing.
• Related要義ようぎWrittenWritten style and rarely used; the essential meaning or underlying principle of a teaching or text.

Use 「骨髄」 for bone marrow itself or figurative expressions of something sinking deep into one, as in 「骨髄移植」「恨み骨髄に徹す」. For the point of a matter say 「要点」 or 「核心」; for the outline of a plan or bill 「骨子」; for the essence 「エッセンス」. The rest cover specific niches: 「趣旨」 intent, 「要旨」 abstracts, 「中核」「中枢」 organizational cores, 「ポイント」 casual speech.

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

1. 骨ほねの中なかの空所くうしょを満みたす柔軟じゅうなんな組織そしき。
2. (比喩ひゆ)心こころの奥底おくそこ。精神的せいしんてきな基礎きそ。
3. (比喩ひゆ)要点ようてん。主眼しゅがん。真髄しんずい。