tri ‧ par ‧ tite /traɪˈpɑːtaɪt $ -ˈpɑːr-/ BrE AmE adjective [only before noun] formal
[ Date: 1400-1500 ; Language: Latin ; Origin: tripartitus , from tri- + partitus 'divided' ]
involving three parts, groups etc
tripartite agreement/talks etc
a tripartite agreement between France, Britain, and Germany