trilateral

adj

1. (not-comparable)Having three sides
2. (not-comparable)Involving three parties

   “The trilateral peace conference, between the red faction, blue faction and white faction, went nowhere.”

   “Meanwhile, a trilateral agreement has been signed with the French and Irish governments committing the nations to keeping freight routes open throughout the pandemic.”

   “Hours later, answering journalists’ questions via a WhatsApp chat, Mr. Zelenskyy said the Trump administration had floated a trilateral meeting in Miami involving the U.S., Ukraine, and Russia.”