‘艰险’ is a compound adjective meaning 'arduous and perilous' — it describes situations, journeys, or tasks that are both extremely difficult (艰) and full of danger or risk (险). The first character 艰 emphasizes hardship, strain, or difficulty in effort or conditions, while 险 conveys danger, hazard, or uncertainty — often physical or environmental. Together, they intensify each other, forming a vivid, literary term commonly used in formal writing, news reports, historical narratives, and descriptive accounts of exploration, rescue missions, or mountain expeditions.

This word carries a strong sense of gravity and solemnity; it’s rarely used for everyday inconveniences (e.g., traffic or minor setbacks). Instead, it evokes images like treacherous mountain passes, stormy seas, wartime campaigns, or high-stakes scientific fieldwork. It functions attributively (e.g., 艰险的旅程) or predicatively (e.g., 这条路十分艰险), and is almost always modified by degree adverbs like 十分, 极其, or 非常 — not by 很 in formal contexts.