Meaning
The kanji 剰 means surplus, excess, remainder, and leftover — whatever stays behind after a primary need has been met. When output, allocation, or supply exceeds what is required, the portion left over is the 剰. In modern Japanese, this character appears mainly in formal and written registers: economics, production, medicine, and quantitative analysis.
Break it down by parts. The left component, 乗, originally conveyed riding upon something or multiplying — the idea of accumulation. The right component, 刂, is the knife radical (vertical form of 刀), which signals cutting or dividing. After riding and multiplying (乗), the knife (刂) cuts away what is distributed — and what it leaves behind is the 剰, the excess.
At 11 strokes, 剰 belongs to the extended Jōyō list (grade 8). It rarely surfaces in everyday conversation but appears steadily in newspapers, business documents, and academic texts — especially in economics, accounting, and mathematics.
Readings
On'yomi (音読み) — Chinese-derived readings
The on'yomi reading is ジョウ (jō), drawn from the classical Chinese pronunciation. It appears almost exclusively in compound words (熟語, jukugo). Whenever 剰 sits alongside 過 or 余 in a compound, the reading will be ジョウ — and in formal written Japanese, that is the reading you will encounter in practice.
- 過剰 (kajō) — excess, surplus, overabundance; the most frequently encountered word using this kanji
- 余剰 (yojō) — surplus, the excess amount remaining after use or allocation
- 剰余 (jōyo) — remainder, surplus; used especially in mathematics and accounting
Kun'yomi (訓読み) — Native Japanese readings
The kun'yomi readings are あま(る) (amaru) and あま(り) (amari) — identical in sound to the far more common 余る and 余り. In modern Japanese, 余 is simply the kanji writers reach for when writing these sounds. 剰 in kun'yomi form belongs to classical or literary texts; outside of historical documents, encountering it this way is rare.
- 剰る (amaru) — to remain, to be left over, to be in excess (classical form of 余る)
- 剰り (amari) — remainder, too much, overly (classical form of 余り, used as noun or adverb)
- 剰す (amasu) — to leave over, to have remaining; the transitive counterpart of あまる
Common Words & Compounds
剰 appears mainly in formal and academic registers. The compounds below are grouped by context.
Economics and Finance:
- 過剰 (kajō) — excess, surplus; having too much relative to demand or need
- 余剰 (yojō) — surplus, the excess remaining after a need has been met
- 剰余金 (jōyokin) — retained earnings, surplus funds; a standard term in accounting and corporate finance
- 剰余価値 (jōyo kachi) — surplus value; in Marxist economics, the value workers create beyond what they are paid
- 余剰人員 (yojō jin'in) — surplus personnel, overstaffing; a workforce larger than operations require
Production and Supply:
- 過剰生産 (kajō seisan) — overproduction, goods produced in excess of market demand
- 過剰供給 (kajō kyōkyū) — oversupply, supply exceeding demand, typically pushing prices down
- 余剰生産物 (yojō seisanbutsu) — surplus product, output beyond what is consumed or needed
Health and Medicine:
- 過剰摂取 (kajō sesshu) — excessive intake, overdose; nutrients, supplements, or medication taken beyond recommended amounts
- 過剰反応 (kajō hannō) — overreaction, an excessive response to a stimulus, physiological or emotional
- 過剰適応 (kajō tekiō) — over-adaptation; a psychology term for excessive conformity to external demands at personal cost
Mathematics:
- 剰余 (jōyo) — remainder after integer division; equivalent to the modulo operation in computing
- 剰余類 (jōyo rui) — residue class; a concept in number theory used in modular arithmetic
Example Sentences
過剰な糖分は健康に悪い。
Kajō na tōbun wa kenkō ni warui.
Excessive sugar is bad for your health.
この工場は過剰生産で倉庫が満杯になった。
Kono kōjō wa kajō seisan de sōko ga manpai ni natta.
This factory's warehouse became full due to overproduction.
余剰人員を他の部署に配置転換した。
Yojō jin'in wo ta no busho ni haichi tenkan shita.
The surplus personnel were reassigned to other departments.
剰余金は来年度の予算に繰り越す。
Jōyokin wa rainendo no yosan ni kurikosu.
The surplus funds will be carried over to next year's budget.
過剰なプレッシャーをかけると、選手が過剰反応することがある。
Kajō na puresshā wo kakeru to, senshu ga kajō hannō suru koto ga aru.
When too much pressure is applied, athletes sometimes overreact.
市場の過剰供給が価格の下落を引き起こした。
Shijō no kajō kyōkyū ga kakaku no geraku wo hikiokoshita.
The oversupply in the market caused prices to fall.
数学の授業で剰余の計算を習った。
Sūgaku no jugyō de jōyo no keisan wo naratta.
I learned how to calculate remainders in math class.
過剰摂取を防ぐため、用量を守ることが大切だ。
Kajō sesshu wo fusegu tame, yōryō wo mamoru koto ga taisetsu da.
Follow the prescribed dosage to avoid excessive intake.
この会社は余剰エネルギーを近隣に売却している。
Kono kaisha wa yojō enerugī wo kinrin ni baikyaku shite iru.
This company sells its surplus energy to neighboring areas.
剰余価値の概念は経済学を学ぶ上で欠かせない。
Jōyo kachi no gainen wa keizaigaku wo manabu ue de kakasenai.
The concept of surplus value is essential when studying economics.
Memory Tip
Picture a samurai who has just finished riding out and multiplying his stores (乗). He gathers so much that even after handing portions to the entire village, a pile sits unclaimed on the ground. Then the knife (刂) cuts off what was taken — and what stays on the ground is the 剰, surplus nobody needed.
The compound you will meet most is 過剰. Fix it with one phrase: "Ka-JŌ? That's just way too much!" Once ジョウ locks in as "way too much," the rest falls into place — leftover funds, surplus staff, a mathematical remainder. All of them are that pile sitting on the ground.