崩溃 (bēng kuì) is a verb meaning 'to collapse' or 'to break down', often describing a sudden, complete failure—whether physical, systemic, or psychological. The character 崩 originally refers to mountains crumbling or structures collapsing violently; 溃 means 'to burst' or 'to disintegrate', as in a breached dam or a defeated army. Together, they emphasize total, irreversible breakdown—not just weakness, but a dramatic loss of integrity or control.

This word is commonly used for mental/emotional collapse (e.g., after prolonged stress), system failures (computers, networks, economies), or structural disasters (buildings, bridges). It carries strong connotations of helplessness and urgency, and is rarely used lightly—it implies severity beyond mere 'stress' or 'failure'. While it can describe literal physical collapse, its most frequent modern usage is metaphorical, especially in discussions of mental health, technology, or social systems.