劫难 (jié nàn) is a formal, literary noun meaning 'calamity' or 'great disaster' — often implying sudden, overwhelming misfortune that causes profound suffering or upheaval. The first character 劫 (jié) originally meant 'to seize by force' or 'robbery', carrying connotations of violent disruption; the second character 难 (nàn) means 'disaster', 'hardship', or 'difficulty'. Together, they intensify each other, suggesting not just ordinary trouble but a catastrophic, life-altering event — frequently used in historical, religious, or literary contexts to describe wars, plagues, natural catastrophes, or existential crises.

This term evokes gravity and solemnity; it’s rarely used for minor setbacks. It appears often in classical texts, Buddhist scriptures (where it refers to cosmic calamities), and modern writing describing national or personal turning points. While grammatically a noun, 劫难 functions as a standalone subject or object and does not take aspect markers (e.g., no 了 or 过). It pairs naturally with verbs like 遭遇 (to encounter), 历经 (to undergo), or 渡过 (to survive).