Three-way

a.

1.

Connected with, or serving to connect, three channels or pipes; as, a three-way cock or valve.

Adj.

1.

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" Synonyms: three-party, trilateral, tripartite, triangular

many-sided, multilateral, three-party, triangular, trilateral, tripartite