- triangular, trilateral, tripartite, three-party, three-way - involving three parties or elements; "the triangular mother-father-child relationship"; "a trilateral agreement"; "a tripartite treaty"; "a tripartite division"; "a three-way playoff"
Antonyms: bilateral, two-sided (indirect, via unilateral, multilateral)
Antonyms: unilateral, one-sided (indirect, via multilateral, bilateral)