1) Four-party 2) Involving four parties 3) Many-sided 4) Multilateral 1) Multilateral 
• (a.) Divided into four parts.
(kwod″rĭ-pahr´tīt) divided into four.
Quad·rip'ar·tite adjective [ Latin quadripartitus , past participle of quadripartire to divide into four parts; quattuor four + partire to divide: confer French quadripartite .] Divided into four parts. 
[adj] - involving four parties
four-party adjective involving four parties
divided into or consisting of four parts. · involving four participants: a quadripartite treaty.