诚实 (chéng shí) is an adjective meaning 'honest' or 'truthful'. It combines two characters: 诚 (chéng), which conveys sincerity, genuineness, and moral integrity; and 实 (shí), which means 'real', 'actual', or 'substantial'. Together, they emphasize alignment between one’s inner convictions and outward words or actions — not just telling the truth, but doing so with sincerity and consistency. The word carries strong positive moral weight in Chinese culture, often associated with trustworthiness, reliability, and ethical character.

诚实 is commonly used to describe people (e.g., a 诚实的孩子), behavior (e.g., 诚实的回答), or values (e.g., 坚持诚实). It frequently appears in educational contexts, family guidance, and formal discussions about ethics or integrity. While it can modify nouns directly, it’s also used predicatively (e.g., 他很诚实) or as a subject complement after 是. It’s more formal and morally loaded than casual synonyms like 实在 (shízài).