微量

• Reading: びりょう
• Romaji: biryō
• Kanji breakdown: 微 (bi) — minute, slight, subtle; 量 (ryō) — quantity, amount, measure
• Pronunciation: /bi.ɾʲo.ɯ/

Meaning

Minute amount; trace quantity; minuscule dose. An extremely small measurable quantity.

A noun and adjectival noun describing an extremely small quantity, often of a substance: 微量の放射線 (a trace amount of radiation), 微量元素 (trace elements). Common in scientific, medical, and food-safety contexts where precise measurement matters. Distinguished from 少量 (shōryō, a small amount) by degree — 微量 implies a quantity so tiny it approaches the detection limit, whereas 少量 simply means not much.

Examples

1. 微量の農薬が検出された。 Trace amounts of pesticide were detected.
2. 微量でも影響がある物質もある。 Some substances have an effect even in trace quantities.
3. この食品には微量のアレルゲンが含まれている。 This food contains trace amounts of allergens.

Usage Guide

Context: science, medicine, food safety

Tone: technical

Origin & History

From Sino-Japanese: 微 (bi, minute/slight/subtle) + 量 (ryō, quantity/amount). The kanji 微 conveys the idea of something barely perceptible, while 量 specifies that it is a measurable quantity — together, a quantity at the threshold of detection.

Cultural Context

Era: Modern

Generation: All ages

Social background: Educated