Translation guide
The English word "sector" has several distinct meanings. This guide covers the most common uses for learners: a distinct part of the economy or society, a military zone, a geometric area, and a computing disk unit. For each meaning, natural Japanese expressions are provided.
Referring to a distinct part of the economy, industry, or society (e.g., private sector, public sector, technology sector).
General term for a division or department within an organization or field. Commonly used for economic sectors.
IT部門は急速に成長している。
The IT sector is growing rapidly.
公共部門と民間部門の違いは何ですか。
What is the difference between the public sector and the private sector?
Loanword from English, often used in business and economic contexts. Sounds slightly more technical or modern.
金融セクターの規制が強化された。
Regulations on the financial sector have been tightened.
Means 'field' or 'area' and can be used for sectors in a broader sense, especially in academic or professional contexts.
彼は教育分野で働いている。
He works in the education sector.
Refers specifically to an industry or business world. Use when talking about a commercial sector.
自動車業界は大きな変革期にある。
The automotive sector is undergoing a major transformation.
A designated area of military operations or control.
General term for a district or zone, commonly used in military contexts for 'sector'.
その部隊は敵の地区に侵入した。
The unit infiltrated the enemy sector.
Specifically means 'war zone' or 'theater of operations'. More formal and military-specific.
司令部は全戦区に命令を下した。
The headquarters issued orders to all sectors.
Also used in military contexts, especially in translated materials or modern settings.
A part of a circle bounded by two radii and an arc, or a similar division in geometry.
The standard mathematical term for a sector of a circle. Literally 'fan shape'.
円の扇形の面積を計算してください。
Please calculate the area of the sector of the circle.
Used in technical or mathematical contexts, often in combination with other terms.
A subdivision of a track on a magnetic or optical disk.
The standard IT term for a disk sector. Note the slightly different katakana spelling from the general loanword.
不良セクタが検出されました。
Bad sectors were detected.
Also used, but セクタ is more common in technical documentation.
Both can mean 'sector' in economic contexts. 部門 is a native Japanese word and feels more integrated into everyday language. セクター is a loanword that often appears in business news or formal reports. For general use, 部門 is safer and more natural.
この部門の成長は目覚ましい。
The growth of this sector is remarkable.
公共セクターの改革が急務だ。
Reform of the public sector is urgent.
The word 区域 (くいき) means 'area' or 'zone' but is not typically used for economic or social sectors. Using it for 'private sector' would sound unnatural. Stick to 部門 or セクター for those meanings.
彼は第3セクターの防衛を担当している。
He is in charge of defending Sector 3.
ハードディスクのセクターが破損した。
The hard disk sector is damaged.
ディスクのセクターサイズを確認する。
Check the disk sector size.