1.
purity; purity level; degree of purity
The proportion of a substance that is pure, free from impurities or contamination. Used for metals, chemicals, water, and other substances.
純度の高い金だ。
It's gold of high purity.
この水は純度99%以上だ。
This water has a purity of over 99%.
半導体の製造には極めて純度の高いシリコンが必要とされる。
Extremely high-purity silicon is required for semiconductor manufacturing.
Common collocations: 純度が高い/低い (high/low purity), 高純度 (high purity — as a compound modifier). The suffix ～度 indicates degree or level, as in 濃度 (concentration), 精度 (precision), 鮮度 (freshness). Gold purity in Japan is expressed as 純度: 24金 (純金, pure gold), 18金 (75% purity). Related: 純粋 (pure — used more broadly, including figuratively for people).