trilateral
adjective uk/ˌtraɪˈlæt.ər.əl/ us/ˌtraɪˈlæt̬.ɚ.əl/
(GROUPS) 涉及三方的;涉及三国的involving three groups or countries
A trilateral summit meeting was planned for the following month. 三方峰会计划在接下来的一个月举行。
(SIDES) mathematics 有三边的having three sides
Related word: trilaterally