有害|ゆうがいyuugai[0]heiban (flat)

1. na-adjective, nounharmful; hazardous
   煙草たばこは健康けんこうに有害ゆうがいである。↗

   Smoking is harmful to your health.

• Synonym悪性あくせいWrittenWritten/formal term used mainly of diseases, as in 「悪性腫瘍」; 「有害」 broadly covers anything harmful to health or the environment.
• Related悪性あくせいWrittenWritten/formal term used mainly of diseases, as in 「悪性腫瘍」; 「有害」 broadly covers anything harmful to health or the environment.
• Related悪いわるいCasualColloquial suffix read 「にくい」 meaning hard to do, as in 「読み難い」; it differs in meaning from 「有害」.
• Related破壊的はかいてきWrittenWritten/formal term meaning destructive; 「有害」 focuses on causing harm to health or the environment.
• Related壊滅的かいめつてきWrittenWritten/formal word for devastating, catastrophic damage; 「有害」 just means harmful in general and does not stress destructive scale.
• Antonym無害むがいNeutralMeans harmless, causing no harm; the direct opposite of 「有害」.
• Antonym安全あんぜんNeutralMeans safe and free from danger; the opposite of 「有害」.

Use 「有害」 for things harmful to health or the environment, as in 「有害物質」. For malignant diseases use 「悪性」, for destructive or catastrophic damage 「破壊的」 or 「壊滅的」; the opposites are 「無害」 and 「安全」.

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

1. 害がいのあること、害がいをもたらすこと。そういうものやその様子ようす。