課|かka[1]atamadaka (head-high)

1. noun, noun (suffix)lesson
   私は１時間じかんではその課かを全部ぜんぶは理解りかいできない。↗

   I can't absorb all of the lesson in an hour.
2. noun, noun (suffix)section (in an organization); division; department
   ウイリアムズ氏しがその課かを取り仕切とりしきっている。↗

   Mr Williams carries that section.
3. countercounter for lessons and chapters (of a book)
   １０課かから始はじめましょう。↗

   Let's start with Lesson Ten.

• SynonymセクションNeutralLoanword for a section or department; broader and vaguer than 「課」.
• Synonym部門ぶもんNeutralGeneric term for any part an organization is divided into, also contest or award categories; 「課」 is a specific unit in a fixed hierarchy, itself one 「部門」.
• Related部局ぶきょくWrittenWritten, bureaucratic term; a blanket word for the bureaus, departments and sections of a government agency. Favors official documents.
• Related分科ぶんかNeutralRefers to a subdivision made by subject or specialty, as in 「分科会」; 「課」 is a section within an organization or a lesson in a textbook.
• Related課業かぎょうWrittenWritten and rare; refers to assigned schoolwork or work tasks. It overlaps with 「課」 only in the schoolwork/lesson sense.
• Related事業部じぎょうぶNeutralA large company division organized around a line of business; it ranks above 「課」 in the corporate hierarchy.

Use 「課」 for a section below the department level in a company or government office, or for a lesson in a textbook. For departments in general say 「部門」 or 「セクション」; for a large business-line division say 「事業部」.

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

1. 会社かいしゃや役所やくしょの機構きこう区分くぶん。一般いっぱんに部ぶの下もとで係かかりの上うえ。
2. 教育きょういく・学習がくしゅう内容ないようの区分くぶん。