She's the peacekeeper in that family.

那个家庭的纠纷都由她来调解。

《牛津词典》

They want the United Nations to play a bigger role as the world's peacekeeper.

他们希望联合国作为世界维和组织发挥更大的作用。

《柯林斯英汉双解大词典》

On behalf of Arab diplomats in China, Ambassador Mhd Kheir Al-Wadi expressed condolences over the death of Du Zhaoyu, a Chinese peacekeeper, in Lebanon, as well as sympathy for his relatives.

瓦迪大使代表阿拉伯国家驻华使节对中国维和人员杜照宇在黎巴嫩遇难表示哀悼，对杜照宇的家属表示慰问。

youdao

People who have worked with Cook at Apple describe him as quiet and confident, the peacekeeper at the conference room table.

CNN: Mark Milian,

Your vote this spring on the Peacekeeper missile will be a critical test of our resolve to maintain the strength we need and move toward mutual and verifiable arms reductions.

CNN: State of the Union Address

In a healthy person the peacekeeper cells predominate.

FORBES: Magazine Article