‘发慌’ is a verb meaning ‘to feel panicky’ or ‘to become suddenly anxious or flustered’. The character 发 (fā) here functions as a verb prefix indicating the onset or emergence of a state, while 慌 (huāng) means ‘flustered’, ‘panicked’, or ‘agitated’. Together, they describe the sudden emergence of nervousness—often triggered by unexpected pressure, danger, or uncertainty. It emphasizes a physical and emotional reaction: rapid heartbeat, sweating, mental blankness, or an urge to flee.

This word is commonly used in spoken Mandarin and informal writing to describe momentary loss of composure. It often appears after subject + time/cause markers (e.g., 一…就…, 突然, 听到…后), highlighting immediacy. While not clinical, it conveys stronger distress than 忐忑 (nervous anticipation) but less intensity than 崩溃 (breakdown). It’s frequently paired with bodily reactions like 手心出汗 (sweaty palms) or 说不出话 (unable to speak).