減り|へりheri[0]heiban (flat)

1. noundecrease; reduction; fall

• Synonym減少げんしょうNeutralThe most general word for a drop in quantity, used in speech and writing alike. 「減り」 is more colloquial, speaking of how much or how fast things are consumed or worn.
• Synonym低下ていかWrittenWritten/formal prose for a fall in ability, quality, figures or levels, as in 「体力の低下」「生産量の低下」; it never describes consumption or wear.
• Synonym下落げらくWrittenWritten/formal prose for a fall in prices or market quotations, as in 「株価の下落」; it centers on market prices, not general decreases.
• Synonym減量げんりょうNeutralA reduction in quantity or weight, often slimming down, as in 「減量に成功」; the focus is on amount or weight, not on how fast everyday things wear down.
• Synonym低減ていげんWrittenWritten/formal prose for lowering quantity or degree, either deliberately cutting costs or risks as in 「コスト低減」 or a natural drop; not for how fast things get used up.
• Synonym減退げんたいWrittenWritten/formal prose for a decline in functions such as appetite or stamina, as in 「食欲減退」; it stresses weakening of faculties, not consumption.
• SynonymさがりCasualColloquial for a fall or drooping, and also for hand-me-downs or offerings taken down from an altar; it never speaks of how fast things wear.
• Synonym減数げんすうWrittenWritten/formal prose for a decrease in number, and also the subtrahend in arithmetic; it is about counting, not wear.
• Synonym減損げんそんWrittenWritten/formal prose, chiefly an accounting term for asset impairment, as in 「減損会計」.
• Synonym累減るいげんWrittenWritten/formal prose for step-by-step, staged decreases; rare, and the counterpart of 「累増」.
• Synonym減げんNeutralReduction, mostly as a prefix or suffix as in 「三割減」; on its own it never speaks of how fast things wear.
• Synonym損減そんげんWrittenWritten/formal prose for decrease or damage; very rare — say 「減少」 instead in most cases.
• Antonym増加ぞうかNeutralAn increase in quantity, the opposite of 「減り」's decrease, as in 「人口増加」.
• Antonym増えCasualColloquial antonym: the degree or speed of increase, the mirror of 「減り」's decrease; seldom used alone.

For a drop in quantity, say 「減少」. 「減り」 is colloquial and speaks of how much or how fast things are consumed or worn, as in 「電池の減りが早い」「靴底の減り」. For falling prices use 「下落」, and for increases 「増加」.

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

1. へること。消耗しょうもうし減少げんしょうすること。また、その量りょう。