立功 (lì gōng) literally means 'to establish merit'—the character 立 (lì) means 'to stand, to set up, to achieve', and 功 (gōng) means 'merit, achievement, or contribution'. Together, the phrase conveys the idea of doing something commendable that benefits others or serves a greater cause, especially in contexts like public service, military duty, medical care, or social responsibility. It carries a formal, positive connotation and is often used in official, institutional, or moral discourse.

The term is commonly associated with recognition—such as being awarded a medal, receiving commendation, or gaining social respect—not for personal gain but for selfless action. While historically tied to wartime or governmental service, modern usage extends to healthcare workers saving lives during crises, scientists making breakthroughs, or volunteers performing extraordinary community service. It implies intentionality, effort, and measurable positive impact.