How to say "reform" in Japanese

• 改革かいかくJLPT N1approx.Common
  noun, suru verb, transitive verbThe default noun for reform: large-scale change to systems, institutions, or policy. Use it for political, economic, or educational reform where the existing structure itself is overhauled.
  「冬ふゆの時代じだい」が大学だいがく改革かいかくの起爆剤きばくざいとなってくれればと思おもう。↗

  So-called "winter time" is expected to enhance the college reform.
• 改良かいりょうJLPT N1approx.Common
  noun, suru verb, transitive verbCovers reform in the sense of improving something to make it better — refining a product, process, or method. The nuance is gradual enhancement of quality rather than overhauling a system.
  コンピューターはたえず改良かいりょうされている。↗

  Computers are constantly being improved.
• 革新かくしんJLPT N1approx.Common
  noun, suru verb, transitive verbUsed for reform that is bold and innovative, often breaking with old ways; its gloss also gives 'innovation'. Suits talk of technological or organizational renewal driven by new ideas.
• 刷新さっしんCommon
  noun, suru verb, transitive verbReform as renovation: refreshing an organization or group, typically by replacing people or practices with new ones. Common for renewing a cabinet, management, or an organization's image.
• 正すただすCommon
  godan verb, transitive verbA verb covering reform in the sense of correcting or rectifying something wrong — bad behavior, mistakes, or injustice. For systematic overhaul, this is not the word you want; it is really about setting things right.
  間違まちがいがあれば正ただしなさい。↗

  Correct errors, if any.

Use 改革 for sweeping institutional change, 改良 for practical improvement of quality, 革新 for innovative change, 刷新 for renewing personnel or organizations, and 「正す」 when reform means correcting wrongdoing.

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

• 改革かいかくreform
• 改良かいりょうimprovement
• 革新かくしんreform
• 刷新さっしんreform
• 正すただすto correct
• 変革へんかくchange
• 一新いっしんcomplete change
• 矯正きょうせいcorrection (of a fault, defect, flaw, etc.)
• 修まるおさまるto reform (oneself)
• 改悟かいごreform
• 更始こうしrenewal
• 刪修さんしゅうrevision
• 魂を入れ替えるたましいをいれかえるto turn over a new leaf
• 心を入れ替えるこころをいれかえるto turn over a new leaf
• 匡正きょうせいcorrection (of a fault, mistake, flaw, etc.)
• 変えるかえるto reform
• 改めるあらためるto reform