天真 (tiān zhēn) literally combines 天 (tiān, 'heaven' or 'nature') and 真 (zhēn, 'true' or 'genuine'), suggesting a quality that is naturally authentic — like the unselfconscious honesty and openness of a young child. It describes someone who is innocent, unsophisticated, and free from worldly cynicism or guile. While often positive — evoking charm, sincerity, and moral purity — it can carry a mild negative connotation when implying unrealistic optimism or lack of practical judgment.

This word is commonly used to describe people (especially children or idealistic adults), behavior, expressions, smiles, or ideas. It appears frequently in literature, film criticism, and everyday conversation when praising sincerity or gently teasing someone’s lack of experience. Unlike words meaning mere 'ignorance', 天真 emphasizes an inherent, almost poetic genuineness — not ignorance born of neglect, but simplicity rooted in trust and openness.