一部・１部|いちぶichibu[2]nakadaka (mid-high)

1. noun, adverbone part; one portion; one section
   一部いちぶの人々ひとびとは日本にっぽんがすべて一番いちばんだと思おもっている。↗

   Some people believe that Japan is No.1 in everything.
2. nounone copy (of a book); (one) complete set (of books)

• Synonym一部分いちぶぶんNeutralEmphasizes a limited portion of the whole; 「一部」 is shorter and more common, and can also mean one copy or one set of books.
• Synonym一端いったんWrittenWritten register: one end or a fragment, often in 「一端を担う」「一端を示す」; 「一部」 is broader in use.
• SynonymパートNeutralLoanword for a part in music, an assigned share of work, or part-time work; 「一部」 is about a block of the whole.
• SynonymセクションNeutralLoanword for a department or a chapter; 「一部」 focuses on a portion of a whole.
• Synonym局所きょくしょWrittenWritten register: a limited local area, as in 「局所麻酔」「局所的な豪雨」; 「一部」 is broader.
• Synonym部分ぶぶんNeutralVery close to 「一部」, but stresses a part as divided off from the whole.
• SynonymポーションNeutralLoanword for a single serving of food or a dose of medicine; 「一部」 is about a part of something.
• Related部門ぶもんNeutralA department of an organization or a category; 「一部」 denotes a part, not an organizational unit.
• Related要素ようそNeutralA constituent element or factor; 「一部」 stresses a limited range within the whole.
• Related成分せいぶんNeutralAn ingredient or component of a substance; 「一部」 is about a block of the whole.
• Related区分くぶんNeutralA division or category produced by sorting; 「一部」 focuses on a limited part.
• Related部署ぶしょNeutralOne's post or department, as in 「部署に就く」; 「一部」 is about a limited part of something.
• Related部ぶNeutralA department or school club, as in 「野球部」; 「一部」 means a part of something.
• Related局部きょくぶNeutralA local area or affected part, also the private parts; 「一部」 carries no medical nuance.
• RelatedパーツNeutralLoanword for parts or components, discrete pieces fitted together to make something; 「一部」 is any share of a whole rather than a separate component.
• Related分野ぶんやNeutralA field or domain, e.g. of study; 「一部」 is about a portion of something.
• RelatedポーションNeutralLoanword for a single serving of food or a dose of medicine; 「一部」 is about a part of something.
• RelatedコンポーネントNeutralLoanword for a component, mainly in IT; 「一部」 is the everyday word.
• RelatedセグメントNeutralLoanword for a market segment or a subdivided block; 「一部」 is more everyday.
• Related構成要素こうせいようそWrittenWritten, academic term for an element that makes up a whole; 「一部」 is more everyday.
• Related構成成分こうせいせいぶんWrittenWritten, academic and rare term for a structural component; 「一部」 is the everyday way to say a part.
• Antonym全部ぜんぶNeutralThe opposite: everything, as in 「全部終わった」, versus 「一部」 for just a portion.
• Antonym全体ぜんたいNeutralThe whole or entirety, opposed to the limited scope of 「一部」.
• Antonym総体そうたいWrittenWritten register: the whole taken as a totality, opposed to the limited 「一部」.

Use 「一部」 for a part of a whole, as in 「一部の人」; it also counts copies or sets of books. To stress a limited portion say 「一部分」; for physical parts or components 「パーツ」; for an organizational unit 「部門」; for a local or affected area of the body 「局部」; and for everything 「全部」. Loanwords like 「セクション」「ポーション」「コンポーネント」「セグメント」 have narrower technical uses, while 「一端」「局所」「構成要素」「総体」 belong to written prose.

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

1. 書物しょもつの一いち組くみ。
2. 雑誌ざっしや書物しょもつなどの一いち冊さつ。
3. 全体ぜんたいの中なかのある部分ぶぶん。
4. 部首ぶしゅ「⼀」で分類ぶんるいした漢字かんじの一群いちぐん。