interlocutor
noun [ C ] formal uk/ˌɪn.təˈlɒk.jə.tər/ us/ˌɪn.t̬ɚˈlɑː.kjə.t̬ɚ/
对话者，参加谈话者
someone who is involved in a conversation
（谈话中的）代言人
someone who is involved in a conversation and who is representing someone else
Abraham was able to act as interpreter and interlocutor for our group. 亚伯拉罕可以充当我们小组的翻译和代言人。