Meaning
廃 (hai) describes things that were once active or useful and have since been abandoned, abolished, or left to decay. A centuries-old law gets 廃止された. A factory dumps 廃水 into the river. A castle becomes 廃墟. Even the waste your body expels is 老廃物. All of these share one thread: a shift from functional to discarded — something that had a role, and no longer does.
Structurally, 廃 combines the radical 广 (まだれ, madare) — a slanted roof or shelter built against a cliff — with a phonetic-semantic component related to 発 (send out, emit, depart). Picture a building whose roof still stands but whose interior has been completely expelled. The 广 shell remains; the 発 content is gone. That image maps cleanly onto the kanji's meaning.
廃 is a Jōyō kanji written with 12 strokes, introduced at the secondary school level. It appears regularly in legal texts, environmental regulations, policy reporting, and historical heritage discussions — making it one of the more practically useful N1 kanji to recognize on sight.
Readings
On'yomi (音読み) — Chinese-derived readings
廃 has one on'yomi: ハイ (hai), borrowed from Middle Chinese. It appears almost exclusively in Sino-Japanese compound words (熟語, jukugo), and you will encounter it far more often than the kun'yomi forms — ハイ dominates in legal documents, environmental law, and journalism.
- 廃止 (haishi) — abolition, repeal; the formal termination of a law, system, or institution
- 廃棄 (haiki) — disposal, abandonment, scrapping; discarding something as no longer usable
- 廃墟 (haikyo) — ruins; the remains of an abandoned building, town, or civilization
- 廃業 (haigyou) — closing down a business; ceasing commercial operations permanently
- 廃車 (haisha) — a scrapped or decommissioned vehicle; a car no longer registered for road use
Kun'yomi (訓読み) — Native Japanese readings
The kun'yomi readings are すた(れる) — sutareru and すた(る) — sutaru. 廃れる (sutareru) is an intransitive ichidan verb meaning "to fall into disuse, to become obsolete, to go out of fashion or practice." Unlike the on'yomi compounds — which often describe deliberate policy decisions — sutareru captures a gradual, organic process of decline. 廃る (sutaru) is a slightly older or more literary form with the same meaning.
- 廃れる (sutareru) — to fall into disuse, to become obsolete, to fade from practice
- 廃れた習慣 (sutareta shuukan) — an obsolete or dying custom
- 廃れゆく技術 (sutareyuku gijutsu) — a craft or technique that is fading away over time
Common Words & Compounds
廃 turns up across legal, environmental, and everyday contexts. Here are the main compound groups worth knowing.
Law, Policy & Administration:
- 廃止 (haishi) — abolition, repeal of a law or institutional system
- 廃絶 (haizetsu) — complete eradication; total abolition (used for nuclear weapons, disease, etc.)
- 廃案 (haian) — a bill or legislative proposal that has been dropped or rejected
- 廃法 (haihou) — the abolition of a law; deregulation through repeal
Environment, Industry & Science:
- 廃棄物 (haikibutsu) — waste material, refuse, garbage; the standard term in environmental law
- 廃水 (haisui) — wastewater, effluent discharged from a factory or facility
- 廃液 (haieki) — waste liquid, spent chemical solution
- 廃熱 (hainetsu) — waste heat; thermal energy lost in industrial processes
- 老廃物 (rouhaibutsu) — metabolic waste products produced by living organisms
Buildings, Infrastructure & Objects:
- 廃墟 (haikyo) — ruins; an abandoned and decaying building or settlement
- 廃屋 (haioku) — an abandoned, uninhabited house
- 廃車 (haisha) — a scrapped or deregistered vehicle
- 廃品 (haihin) — scrap goods, discarded articles
- 廃線 (haisen) — a discontinued or decommissioned railway line
People & Business:
- 廃業 (haigyou) — permanently closing down a business, shop, or trade
- 廃人 (haijin) — an invalid or someone rendered completely incapacitated; used with strong nuance
Example Sentences
その古い法律は昨年廃止された。
Sono furui houritsu wa sakunen haishi sareta.
That old law was abolished last year.
廃墟となった城が山の上に静かに立っている。
Haikyo to natta shiro ga yama no ue ni shizuka ni tatte iru.
The ruins of a castle stand quietly on top of the mountain.
産業廃棄物の不法投棄は厳しく禁止されている。
Sangyou haikibutsu no fuhou touki wa kibishiku kinshi sarete iru.
Illegal dumping of industrial waste is strictly prohibited.
その地域の伝統的な習慣はすっかり廃れてしまった。
Sono chiiki no dentouteki na shuukan wa sukkari sutarete shimatta.
The traditional customs of that region have completely fallen out of use.
工場から排出される廃水が近くの川を汚染している。
Koujou kara haishutsusareru haisui ga chikaku no kawa wo osen shite iru.
Wastewater discharged from the factory is polluting the nearby river.
彼の会社は経営難により廃業を余儀なくされた。
Kare no kaisha wa keieinan ni yori haigyou wo yoginaku sareta.
His company was forced to shut down due to financial difficulties.
核兵器の廃絶は国際社会全体の悲願だ。
Kakuheiki no haizetsu wa kokusai shakai zentai no higan da.
The total elimination of nuclear weapons is the long-cherished aspiration of the entire international community.
廃線になった鉄道の跡を歩く旅が若者の間で人気だ。
Haisen ni natta tetsudou no ato wo aruku tabi ga wakamono no aida de ninki da.
Traveling along the tracks of discontinued railway lines has become popular among young people.
体内の老廃物を効率よく排出するために、水分を十分に摂ることが大切だ。
Tainai no rouhaibutsu wo kouritsuyoku haishutsusuru tame ni, suibun wo juubun ni toru koto ga taisetsu da.
Drinking enough water helps the body flush out metabolic waste efficiently.
Memory Tip
Picture a grand shelter with a slanted roof — that is the 广 (madare) radical. Now imagine everything inside being expelled: furniture, people, purpose — all departing like 発 (depart, emit). The roof still stands, but the interior is empty, silent, and crumbling. Something was once here. Nothing remains.
When you see the 广 canopy over the complex interior, think: "The structure survived, but its purpose didn't." Vietnamese learners have a direct shortcut: PHẾ — phế tích (ruins), phế bỏ (discard) — same sound, same meaning.