纯净 (chún jìng) is an adjective meaning 'pure' or 'clean', especially when describing substances like water, air, or other materials free from impurities or contaminants. The character 纯 means 'pure' or 'unmixed', emphasizing absence of foreign elements; 净 means 'clean' or 'free from dirt or pollution', highlighting physical or chemical purity. Together, they form a compound that stresses both qualitative integrity and physical cleanliness — stronger and more formal than either character alone.

This word is commonly used in health, environmental, and consumer product contexts: e.g., 纯净水 (purified drinking water), 纯净空气 (clean air), or 纯净原料 (pure raw materials). It often appears in advertising, scientific descriptions, or official standards, and carries a positive, trustworthy connotation. Unlike everyday terms like 干净 (gānjìng, 'tidy'), 纯净 implies rigorous removal of microscopic or chemical impurities, not just surface-level cleanliness.