‘续命’ literally means 'to continue life' — combining 续 (xù, 'to continue, to renew') and 命 (mìng, 'life, fate, or vital energy'). In formal contexts, it can refer to medical interventions that extend life, such as life support. However, in everyday spoken Chinese — especially among young people — it’s used humorously or self-deprecatingly to describe barely surviving a difficult situation: staying awake during an all-nighter, finishing a huge workload just before deadline, or recovering from exhaustion after intense work or study.

The phrase carries strong colloquial flavor and is rarely used in serious medical writing; instead, terms like 延长寿命 (yáncháng shòumìng, 'to extend lifespan') or 维持生命 (wéichí shēngmìng, 'to sustain life') are preferred there. It often appears in internet slang, memes, and casual conversation to exaggerate one’s physical or mental depletion — implying survival is temporary and precarious, not heroic or permanent.