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.
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).