‘侦查’ (zhēn chá) is a formal noun meaning ‘criminal investigation’ — the official process conducted by police or procuratorial organs to gather evidence, identify suspects, and determine facts in a criminal case. The first character 侦 (zhēn) means ‘to investigate secretly or discreetly’, often implying surveillance or intelligence-gathering; the second character 查 (chá) means ‘to examine, inspect, or check’. Together, they emphasize a systematic, authorized inquiry into illegal activity — not casual fact-finding or personal curiosity.

This term appears almost exclusively in legal, judicial, or law enforcement contexts: in news reports about crimes, official documents, court proceedings, or police work. It is never used for everyday checking (e.g., checking homework or weather), nor for medical tests — those use terms like 检查 (jiǎnchá). ‘侦查’ carries institutional weight and implies state authority; it is neutral in tone but highly formal and technical.