'坠机' (zhuì jī) literally combines 坠 (zhuì), meaning 'to fall' or 'to plummet', and 机 (jī), short for 飞机 (fēijī, 'aircraft'). Together, it specifically denotes an aircraft crash — an uncontrolled, often catastrophic descent resulting in destruction. Unlike general terms for accidents, 坠机 implies the aircraft was airborne before crashing, distinguishing it from ground incidents like runway overruns or taxiing collisions.

This term is used almost exclusively in formal, factual contexts: news reports, aviation safety briefings, official investigations, and historical accounts. It carries serious, somber connotations and is rarely used in casual speech or metaphorically. While technically applicable to any flying machine (e.g., helicopters or drones), in practice it most commonly refers to commercial or military airplanes and is strongly associated with loss of life and major disasters.