悪化|あっかakka[0]heiban (flat)

JLPT N1approx.Common
Definitions
  1. noun, suru verb, intransitive verbdeterioration; getting worse; worsening; aggravation; degeneration; corruption
    日ひが経たつにつれて、天気てんきは次第しだいに悪化あっかしつつあった。↗
    The weather was getting worse and worse as the day went on.
Conjugation
Dictionary form悪化する(あっかする)
Polite (masu)悪化します(あっかします)
Negative (nai)悪化しない(あっかしない)
polite (masen)悪化しません(あっかしません)
classical zu / nu悪化せず・悪化せぬ(あっかせず・あっかせぬ)
Past (ta)悪化した(あっかした)
polite (mashita)悪化しました(あっかしました)
Past negative (nakatta)悪化しなかった(あっかしなかった)
polite (masen deshita)悪化しませんでした(あっかしませんでした)
Te form悪化して(あっかして)
Potential悪化できる(あっかできる)
Passive悪化される(あっかされる)
Causative悪化させる(あっかさせる)
Causative passive悪化させられる(あっかさせられる)
Conditional (ba)悪化すれば(あっかすれば)
tara悪化したら(あっかしたら)
Volitional悪化しよう(あっかしよう)
polite (mashou)悪化しましょう(あっかしましょう)
Imperative悪化しろ(あっかしろ)

Common forms generated by rule; see the senses for honorific or irregular usage.

Synonyms & antonyms
  • Synonym劣化れっかNeutralDescribes a decline in quality or performance — materials, equipment, image quality, as in 「経年劣化」. 「悪化」 is for illness, situations or relationships getting worse.
  • Synonym深刻化しんこくかWrittenRefers to a problem or situation becoming more serious, as in 「問題が深刻化する」; common in news writing. 「悪化」 applies more broadly.
  • Related低下ていかNeutralRefers to ability, quality or levels dropping — the emphasis is on a degree going down. 「悪化」 describes situations, illness or relationships turning bad.
  • Related衰弱すいじゃくNeutralRefers to strength failing — physical or mental, as in 「神経衰弱」. 「悪化」 describes a situation getting worse and is not limited to the body.
  • Related高じるこうじるNeutralMeans an intensity growing stronger — interest or enthusiasm deepening, as in 「趣味が高じて」, or a state intensifying. 「悪化」 only covers things turning worse.
  • Related増悪ぞうあくWrittenA medical term for a disease or symptoms worsening, seen mainly in medical writing. In everyday speech use 「悪化」.
  • Related高ずるこうずるWrittenAn older alternative form of 「高じる」 with the same sense — interest intensifying or a state worsening. Everyday speech prefers 「高じる」.
  • AntonymかいぜんNeutralAntonym: making bad points better or a situation improving. 「改善する」 works as both transitive and intransitive: 「状況を改善する」, 「症状が改善する」.
  • Antonym好転こうてんNeutralAntonym: a situation turning for the better; intransitive only, as in 「景気が好転する」 or 「病状が好転する」. The exact counterpart to 「悪化」.

Default to 「悪化」 for situations, illness or relationships turning worse. Use 「劣化」 for quality or performance wearing out, 「低下」 for falling ability or levels, 「深刻化」 for problems growing more serious. Antonyms: 「改善」, 「好転」.

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

Japanese definitions
  1. 悪わるくなること。
  2. 悪わるくなる。
Kanji in this word
English equivalents
See also

JLPT vocabulary levels are community estimates, not official (no official lists have been published since the 2010 revision).

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