Meaning
害 means harm, damage, or injury — physical, financial, environmental, or social. You'll find it in news headlines, legal documents, disaster reports, and everyday speech.
Structurally, 害 is an ideographic compound (会意文字). The top element is 宀 (ukanmuri), the roof radical, suggesting shelter or enclosure. Below sits a structure sometimes read as something sharp or blade-like hidden within that enclosed space. The classical image: something dangerous lurks beneath a roof — harm concealed where you'd expect safety. Whether the etymology is exact or not, the image holds.
害 has 10 strokes and is taught in Grade 4 (小学4年生) — around age 9–10. It appears often in N2 reading passages, and its compounds come up constantly in formal and journalistic Japanese.
Readings
On'yomi (音読み) — Chinese-derived readings
害 has one on'yomi: ガイ. This single reading is used across all compound words (熟語) containing 害, whether the context is formal or casual. It entered Japanese from Middle Chinese and carries the full weight of damage, harm, and destructive effect.
Key ガイ compounds:
- 被害 (higai) — harm received; used when describing a victim's losses
- 損害 (songai) — financial or material damage
- 公害 (kōgai) — environmental pollution, public nuisance
- 障害 (shōgai) — obstacle, impediment, or disability
- 有害 (yūgai) — harmful, hazardous
Kun'yomi (訓読み) — Native Japanese readings
害 has no kun'yomi. Like many kanji borrowed primarily through written texts, it was never paired with a pre-existing native Japanese word. Every instance of 害 in written Japanese is read as ガイ — no exceptions.
Common Words & Compounds
These compounds are grouped by theme to help you spot the patterns.
Damage and Loss
- 被害 (higai) — damage or harm received; standard in disaster and crime reporting: 台風の被害 (typhoon damage)
- 損害 (songai) — loss, especially financial; appears in 損害賠償 (compensation for damages)
- 危害 (kigai) — physical danger directed at a person
- 傷害 (shōgai) — bodily injury; legal term in 傷害罪 (assault and battery)
Environmental and Social Harm
- 公害 (kōgai) — industrial pollution, public nuisance; a central issue in Japan's postwar environmental history
- 害虫 (gaichū) — pest; insects that damage crops or spread disease
- 害悪 (gaiaku) — harmful influence; a serious destructive force in society or morality
Obstruction and Infringement
- 障害 (shōgai) — obstacle; also physical or mental disability: 視覚障害 (visual impairment)
- 妨害 (bōgai) — obstruction, interference with someone's activities or rights
- 侵害 (shingai) — infringement, violation: 著作権侵害 (copyright infringement)
Harmful vs. Harmless
- 有害 (yūgai) — harmful, noxious: 有害物質 (hazardous substance)
- 無害 (mugai) — harmless, safe: 環境に無害 (harmless to the environment)
- 利害 (rigai) — interests, stakes: 利害関係 (conflicting interests, stakeholders)
Causing Harm
- 加害 (kagai) — inflicting harm; the perpetrator's side (contrast with 被害)
- 殺害 (satsugai) — killing, murder; used in formal and legal contexts
Example Sentences
台風による被害は非常に大きかった。
Taifū ni yoru higai wa hijō ni ōkikatta.
The damage from the typhoon was extremely severe.
この化学物質は人体に有害です。
Kono kagaku busshitsu wa jintai ni yūgai desu.
This chemical is harmful to the human body.
農家は害虫から作物を守っている。
Nōka wa gaichū kara sakumotsu wo mamotte iru.
Farmers protect their crops from pests.
この地域では、工場の排気ガスによる公害が深刻な問題になっている。
Kono chiiki de wa, kōjō no haiki gasu ni yoru kōgai ga shinkoku na mondai ni natte iru.
Air pollution from factory exhaust has become a serious problem in this area.
彼は著作権侵害で訴えられた。
Kare wa chosakuken shingai de uttaerareta.
He was sued for copyright infringement.
その計画には複雑な利害関係がある。
Sono keikaku ni wa fukuzatsu na rigai kankei ga aru.
That plan involves some complex competing interests.
交通妨害は法律で禁止されている。
Kōtsū bōgai wa hōritsu de kinshi sarete iru.
Obstructing traffic is prohibited by law.
この薬は副作用がなく、体に無害です。
Kono kusuri wa fukusayō ga naku, karada ni mugai desu.
This medicine has no side effects and is safe for the body.
視覚障害のある人たちへの支援が必要だ。
Shikaku shōgai no aru hitotachi e no shien ga hitsuyō da.
We need better support for people with visual impairments.
公害訴訟では、加害企業が損害賠償を支払うことになった。
Kōgai soshō de wa, kagai kigyō ga songai baishō wo harau koto ni natta.
In the pollution lawsuit, the offending company was ordered to pay compensation for damages.
Memory Tip
Picture a roof (宀) — a symbol of safety. But something sharp is hidden beneath it. That's 害: harm concealed where you'd least expect it.
Shortcut: "harm hides under the roof." For the sound, ガイ rhymes with the English word "guy" — imagine a shady guy lurking under your ceiling, ready to cause trouble.