'Wú jì yú shì' literally means 'not beneficial to the matter' — each character contributes: 无 (wú) = 'not', 济 (jì) = 'to help or relieve', 于 (yú) = a preposition meaning 'toward' or 'regarding', and 事 (shì) = 'matter' or 'affair'. Together, the phrase expresses that an action, effort, or measure fails to produce any useful effect — it’s futile, ineffective, or pointless.

This idiom is formal and often used in written Chinese or serious spoken contexts, such as discussing medical treatments, policy responses, or crisis management. It implies a sober assessment of failure despite intention or effort. Unlike colloquial phrases like '没用' (méi yòng), 无济于事 carries a tone of measured disappointment or resignation, not casual dismissal. It typically follows subjects indicating attempts (e.g., efforts, remedies, warnings) and functions predicatively — never as a noun or modifier.