挺住 literally means 'to hold up' or 'to prop up', combining 挺 (tǐng), meaning 'to extend, to stand upright, to endure', and 住 (zhù), a resultative complement meaning 'to stop, to stay in place'. Together, they form an imperative or descriptive verb meaning 'to hold on', 'to endure', or 'to keep going'—especially in physically or emotionally difficult situations. It often carries urgency and encouragement, like urging someone not to collapse under pressure, pain, stress, or exhaustion.

The phrase is commonly used in spoken Mandarin and informal writing. It’s frequently heard in medical contexts (e.g., urging a patient during treatment), crisis moments (e.g., natural disasters or accidents), or everyday struggles (e.g., staying awake while studying). Though grammatically a verb, it functions most naturally as an intransitive verb or an imperative command—rarely takes an object. It implies resilience without implying success; just enduring the moment is enough.