悪質|あくしつakushitsu[0]heiban (flat)

1. na-adjective, nounmalicious; vicious; malignant; underhanded
   悪質あくしつなドライバーは免許証めんきょしょうを取り上とりあげるべきだ。↗

   Bad drivers should have their licenses taken away from them.
2. na-adjective, nounshoddy; inferior; poor-quality; second-rate

• Synonym邪悪じゃあくWrittenWritten/formal prose. Evil in heart and deed, common in religion and stories; 「悪質」 points to nasty methods and can also mean poor quality.
• Synonym極悪ごくあくWrittenWritten/formal prose. Utterly vicious, as in 「極悪非道」; far stronger than 「悪質」 and never used of poor quality.
• Synonym意地悪いじわるNeutralNeutral. Deliberately mean or spiteful, mostly between people; 「悪質」 describes nasty methods in crime, sales tricks and the like.
• Synonym悪いわるいCasualColloquial. 「憎い」 is hateful and detestable, or ironically admirable; 「悪質」 describes nasty behavior or shoddy quality without emotional coloring.
• Synonym邪よこしまWrittenWritten/formal prose. A noun for evil, evil thoughts or a wicked person, mostly in writing; 「悪質」 is a na-adjective for nasty acts or shoddy quality.
• Synonym不良ふりょうNeutralNeutral. Poor in quality or condition, as in 「不良品」, also delinquents; both can mean poor quality, but 「不良」 is more neutral.
• Synonym極道ごくどうCasualColloquial. Living in vice or dissipation, also the underworld; 「悪質」 describes nasty behavior, nature or quality.
• Synonym悪辣あくらつWrittenWritten/formal prose. Crafty and ruthless in one's methods; 「悪質」 is more common in speech and also covers poor quality.
• Synonym底意地悪いそこいじわるいCasualColloquial. Mean and ill-intentioned at heart, said of people; 「悪質」 describes nasty acts and methods.
• Synonym奸邪かんじゃWrittenWritten/formal prose. A noun for wicked people or things, rare even in writing; everyday speech uses 「悪質」 or 「邪悪」.
• SynonymあくどいCasualColloquial. Over-the-top and shady in method, also of overly strong colors or flavors; 「悪質」 sounds more objective and can mean shoddy.
• Synonym腹黒いはらぐろいCasualColloquial. Scheming behind an innocent face, describing a person's heart; 「悪質」 focuses on nasty behavior.
• Synonym佞悪ねいあくWrittenWritten/formal prose. A twisted, perverse mind or such a person, rare in use; everyday speech says 「悪質」 or 「性悪」.
• Synonym邪曲じゃきょくWrittenWritten/formal prose. Crooked in heart and wicked in conduct, rare in use; everyday speech prefers 「邪悪」 or 「悪質」.
• Related非道ひどうWrittenWritten/formal prose. Cruel and against reason or humanity; 「悪質」 stresses the nasty nature of an act and can also cover shoddy quality.
• RelatedひどいCasualColloquial. Cruel, or just terrible and severe — very broad and the everyday default; 「悪質」 suggests deliberate nastiness or poor quality.
• Related不正ふせいNeutralNeutral. Wrongdoing that breaks the rules, as in 「不正行為」; 「悪質」 stresses the nasty nature of an act and can also mean poor quality.
• Related不当ふとうNeutralNeutral. Unjust or unreasonable, as in 「不当解雇」; 「悪質」 stresses malice or poor quality.
• Related悪あくNeutralNeutral. A noun for evil, or for the villain; 「悪質」 is a na-adjective describing a nasty nature or poor quality.
• Related凶悪きょうあくNeutralNeutral. Brutal and capable of violence, as in 「凶悪犯」; 「悪質」 does not necessarily involve violence.
• Related邪じゃWrittenWritten/formal prose. A noun for evil, evil thoughts or a wicked person, mostly in writing; 「悪質」 is a na-adjective for nasty acts or shoddy quality.
• RelatedいかがわしいNeutralNeutral. Suspicious or unreliable, also indecent, as in 「いかがわしい商売」; 「悪質」 stresses how nasty something is.
• Related不徳義ふとくぎWrittenWritten/formal prose. Immoral and dishonest, rare in use; 「悪質」 leans toward nasty methods and can also mean poor quality.
• Related罪作りつみつくりCasualColloquial. Hurting people's feelings, often half-teasing as in 「罪作りな人」; 「悪質」 carries a stern tone.
• Antonym良質りょうしつNeutralNeutral. Good in quality or nature, as in 「良質なたんぱく質」; the direct opposite of 「悪質」 in its poor-quality sense.
• Antonym上質じょうしつNeutralNeutral. Top-grade quality, typical of paper, goods and services; the opposite of 「悪質」 in its poor-quality sense.

Use 「悪質」 for deliberate, nasty conduct or poor quality, as in 「悪質な詐欺」. For sheer brutality pick 「凶悪」, for rule-breaking or unfairness 「不正」, and in daily talk about something terrible 「酷い」. For evil in stories or religion try 「邪悪」; for extreme viciousness 「極悪」; for personal meanness 「意地悪」 or 「腹黒い」. Antonyms: 「良質」, 「上質」.

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

1. 品質ひんしつ・性質せいしつが悪わるいこと。
2. 品質ひんしつ・性質せいしつが悪わるいさま。