How to say "radical" in Japanese

• 過激かげきCommon
  na-adjective, nounCovers radical in the sense of extreme: radical ideas or measures that go beyond what is moderate, and it also describes violent language. It implies extremism rather than mere thoroughness.
  彼かれの考かんがえは私には過激かげきすぎます。↗

  His ideas are too extreme for me.
• 部首ぶしゅJLPT N2approx.Common
  nounThe radical of a kanji character — the component under which characters are classified in dictionaries. It has only this specialized sense and never means radical in the political or scientific sense.
• ラジカルCommon
  na-adjectiveA loanword used for radical ideas, opinions, or approaches that depart sharply from the conventional, and also for the scientific sense of a free radical.
• 先鋭せんえいCommon
  na-adjective, no-adjectiveCovers radical as sharp or acute: a pointed, intensely honed argument, stance, or approach. It suggests edge and intensity rather than comprehensive change or extremism.
• 抜本的ばっぽんてきCommon
  na-adjectiveMatches radical meaning drastic and thoroughgoing, as in radical reform or revision: change that reaches the roots of a problem. It implies fundamental restructuring, not extremism.
  システム全体ぜんたいを抜本的ばっぽんてきに変かえなければ、この欠点けってんを克服こくふくすることは困難こんなんである。↗

  It is difficult to overcome this shortcoming without drastically changing the whole system.

Use 過激 for extreme or violent radicalism, 部首 for the radical of a kanji, 「ラジカル」 for radical ideas or the scientific sense, 先鋭 for sharp, acute radicalism, and 抜本的 for drastic, thoroughgoing reform.

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

• 過激かげきextreme (measure, idea, etc.)
• 部首ぶしゅradical (of a kanji character)
• ラジカルradical
• 先鋭せんえいradical
• 抜本的ばっぽんてきdrastic
• 急激きゅうげきsudden
• アングラunderground (film, theater, etc.)
• 急進主義者きゅうしんしゅぎしゃradical (person)
• 矯激きょうげきradical
• 急進的きゅうしんてきradical
• 根基こんきradical
• 冪根べきこんnth root
• アンダーグラウンドunderground (film, theater, etc.)
• １８０度ひゃくはちじゅうどcomplete (about-face; in policy, opinion, etc.)
• 根こんradical (esp. one that tends to ionize easily)
• 尖ったとがったprovocative
• 基き(free) radical