禁不起 is a verb phrase meaning 'cannot withstand' or 'is too fragile for' something—typically stress, pressure, illness, cold, heat, or emotional strain. It combines 禁 (jīn, 'to bear/tolerate'), 不 (bù, negation), and 起 (qǐ, a resultative complement indicating capability or effect). Literally, it means 'cannot bear up'—implying a lack of resilience or physical/mental endurance. It’s commonly used in spoken and written Mandarin to describe people, bodies, objects, or situations that fail under minimal challenge.

This phrase often appears with nouns like 风 (wind), 冷 (cold), 累 (fatigue), or 惊 (shock), and usually follows the subject directly: Subject + 禁不起 + Noun. It carries a slightly colloquial, empathetic tone—frequently used when expressing concern for someone’s fragility, especially regarding health or age. Unlike formal alternatives like 无法承受, 禁不起 feels more natural in everyday speech and conveys vulnerability with nuance.