‘私心’ literally combines ‘私’ (sī), meaning ‘private,’ ‘personal,’ or ‘selfish,’ and ‘心’ (xīn), meaning ‘heart’ or ‘mind.’ Together, it refers to a hidden, self-serving motive—something one desires or intends for personal gain rather than for fairness, duty, or the common good. It carries a mildly negative connotation, implying a lack of impartiality or sincerity.

This term is commonly used in discussions about ethics, leadership, relationships, or decision-making—especially when questioning someone’s integrity or transparency. While not as harsh as ‘贪心’ (greed) or ‘虚伪’ (hypocrisy), ‘私心’ suggests a subtle but consequential bias rooted in self-interest. It often appears in formal writing, news commentary, and moral reflection, and is rarely used in casual small talk unless critiquing behavior.