信义 (xìn yì) is a formal noun referring to the moral quality of being faithful to one's word and obligations — trustworthiness, honor, and integrity. Unlike English 'faith' (which can imply religious belief), 信义 strictly applies to interpersonal and social conduct, especially in keeping promises, contracts, or codes of honor. You often see it as the object of verbs like 讲 (to uphold) or 重 (to value), and it is a core virtue in Chinese business and personal ethics.