What it means
Help! Literally "save life." Reserved for genuine emergencies.
When to use it
Shout it loudly and repeatedly — it's what bystanders expect to hear. For a minor problem, 请帮帮我 (please help me) is more appropriate.
Examples
jiù救mìng命！yǒu有rén人yūn晕dǎo倒le了！
Help! Someone has fainted!
jiù救mìng命a啊！
Help!
kuài快lái来rén人，jiù救mìng命！
Someone come quickly, help!
The full set of survival phrases for greetings, dining, shopping, and getting around, each with audio.