trialogue
noun [ C ] uk/ˈtraɪ.ə.lɒɡ/ us/ˈtraɪ.ə.lɑːɡ/ (also trilogue, /ˈtraɪ.lɒɡ/ /ˈtraɪ.lɑːɡ/)
三边对话，三方对话
a conversation or discussion between three people or groups
The policy makers involved in the trialogue were unable to reach agreement. 参与三方会谈的政策制定者未能达成协议。
trilogue discussions on EU data protection 关于欧盟数据保护的三边讨论