negotiator
noun [ C ] uk/nɪˈɡəʊ.ʃi.eɪ.tər/ us/nɪˈɡoʊ.ʃi.eɪ.t̬ɚ/
谈判者;（通常指职业的）谈判专家
someone who tries to help two groups who disagree to reach an agreement with each other, usually as a job
Some very skilful negotiators will be needed to settle this dispute. 解决这一纠纷需要一些非常老练的谈判专家。