trilateraladjective
/ˌtraɪˈlæt.ər.əl//-ˈlæt̬.ɚ-/trilateral adjective (GROUPS)
involving three groups or countries:
A trilateral summit meeting was planned for the following month.
trilateral adjective (SIDES)
mathematics having three sides:
trilateral shapes
trilaterally
adverb /-li/