救命 / 救 + 命
救命 (jiùmìng) means "to save a life" or, when used as an exclamation, "Help!" It combines 救 (to save) with 命 (life). It can be used literally to describe a life-saving action or figuratively and humorously to describe something that provides great relief.
医生说那个药救了他的命。
Yīshēng shuō nàge yào jiù le tā de mìng.
The doctor said that medicine saved his life.
救命!有人掉进河里了!
Jiùmìng! Yǒu rén diào jìn hé lǐ le!
Help! Someone fell into the river!
大热天来一杯冰水,简直是救命啊。
Dà rè tiān lái yī bēi bīng shuǐ, jiǎnzhí shì jiùmìng a.
A glass of ice water on a scorching day is an absolute lifesaver.