死心 (sǐ xīn) literally means 'dead heart'—combining 死 (sǐ, 'to die') and 心 (xīn, 'heart' or 'mind'). Figuratively, it describes the emotional state of completely giving up hope or abandoning a desire, often after prolonged effort or disappointment. It implies finality and resignation, not just temporary discouragement.

This expression is commonly used in personal, relational, or goal-oriented contexts—such as ending romantic pursuit, accepting failure in a job application, or letting go of an unattainable dream. It carries a slightly somber or pragmatic tone, and is more frequent in spoken Chinese than formal writing. While it can sound blunt, it’s not inherently rude; its appropriateness depends on context and relationship closeness.