害する|がいするgaisuru[3]nakadaka (mid-high)
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- suru verb (irregular), transitive verbto injure; to damage; to harm; to hurt
- suru verb (irregular), transitive verbto kill
- suru verb (irregular), transitive verbto hinder; to obstruct
Conjugation
| Dictionary form | 害する(がいする) |
|---|---|
| Polite (masu) | 害します(がいします) |
| Negative (nai) | 害しない(がいしない) |
| polite (masen) | 害しません(がいしません) |
| classical zu / nu | 害せず・害せぬ(がいせず・がいせぬ) |
| Past (ta) | 害した(がいした) |
| polite (mashita) | 害しました(がいしました) |
| Past negative (nakatta) | 害しなかった(がいしなかった) |
| polite (masen deshita) | 害しませんでした(がいしませんでした) |
| Te form | 害して(がいして) |
| Potential | 害できる(がいできる) |
| Passive | 害される(がいされる) |
| Causative | 害させる(がいさせる) |
| Causative passive | 害させられる(がいさせられる) |
| Conditional (ba) | 害すれば(がいすれば) |
| tara | 害したら(がいしたら) |
| Volitional | 害しよう(がいしよう) |
| polite (mashou) | 害しましょう(がいしましょう) |
| Imperative | 害しろ(がいしろ) |
Common forms generated by rule; see the senses for honorific or irregular usage.
- Synonym損じるそんじるWrittenMeans damaging or injuring things; leans written. 「害する」focuses on harming health or feelings.
- Synonym痛めるいためるNeutralTo injure or cause pain, and also to worry; 「害する」centers on doing harm.
- Synonym毀損きそんWrittenDamages reputation or objects; often legal. 「害する」focuses on doing harm.
- Synonym損ねるそこねるNeutralHarms mood or health, or means missing a chance, as in 「機嫌を損ねる」; 「害する」is more written.
- Synonym損傷そんしょうNeutralNoun for injury or damage, objective in tone; 「害する」is a verb.
- Synonym損害そんがいNeutralNoun covering losses and damage of all kinds—financial, physical, reputational, mental, as in 「精神的損害」; 「害する」is a verb.
- Synonym傷害しょうがいWrittenNoun for inflicting bodily injury on someone; legal flavor.
- Synonym破損はそんWrittenNoun for damage to objects; 「害する」focuses on doing harm.
- Synonym損壊そんかいWrittenNoun for buildings, implements or vehicles being damaged; objective, news-report tone. 「害する」targets health or feelings.
- Synonym殺害さつがいWrittenNoun for killing or murdering someone; 「害する」is broader.
- Synonym傷つけるきずつけるNeutralInjures bodies or objects, and hurts feelings or pride, as in 「心を傷つける」; common in speech. For harming health, use 「害する」.
- Synonym損なうそこなうNeutralHarms health or mood, as in 「健康を損なう」; close to 「害する」and common in both speech and writing.
- Synonym害すがいすWrittenLiterary form of 「害する」; written style, same meaning.
- Synonym殺めるあやめるWrittenWritten word for wounding or killing, with an archaic flavor; 「害する」is broader.
- Synonym毀傷きしょうWrittenWritten word for destroying or injuring bodies and objects alike; rare today—use 「損傷」in everyday speech.
- Related阻害そがいWrittenNoun for obstructing progress or development; 「害する」focuses on doing harm.
- Related妨害ぼうがいNeutralNoun for hindering or interfering; 「害する」focuses on doing harm.
- Related阻むはばむWrittenVerb for blocking someone's advance; 「害する」is about being harmful.
- Related阻止そしNeutralNoun for stopping or preventing something; 「害する」focuses on doing harm.
- Related邪魔じゃまNeutralBeing in the way or a nuisance; 「害する」focuses on harming health or feelings.
- Related差し支えるさしつかえるNeutralTo interfere with something or cause inconvenience; 「害する」focuses on doing harm.
- Related妨げるさまたげるNeutralTo hinder or obstruct; 「害する」is about being harmful.
- Related毒するどくするWrittenTo corrupt or poison minds; 「害する」focuses on doing harm.
- Related邪魔立てじゃまだてNeutralDeliberate obstruction or trouble-making; 「害する」focuses on doing harm.
- Related討ち果たすうちはたすWrittenTo slay or cut down an enemy, with an archaic flavor; 「害する」can also mean to kill.
- Antonym助けるたすけるNeutralTo help or assist; the opposite of harmful 「害する」.
- Antonym益するえきするWrittenTo benefit or be of use to someone; the opposite of harmful 「害する」.
Use 「害する」for harming health or feelings or endangering others, as in 「健康を害する」「気分を害する」. You can also say 「健康を損なう」or 「機嫌を損ねる」. For injuring someone or something, use 「傷つける」; for benefiting, 「益する」.
Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only


