multilateral

adj. having many sides (of an agreement, contract, or discussion, etc.); involving two or more states (Government)

Multilateralism is a term in international relations that refers to multiple countries working in concert on a given issue.Most international organizations, such as the United Nations and the World Trade Organization, OSCE are multilateral in nature. The main proponents of multilateralism have traditionally been the middle powers such as Canada, Australia and the Nordic countries. Larger states often act unilaterally, while the smaller ones may have little direct power at all in international affairs aside from participation in the United Nations (by consolidating their U.N. vote in a voting bloc with other nations, for example). Moreover, multilateralism involves all nations acting together as in the UN and does not involve regional or military alliances, pacts or groupings.
See more at Wikipedia.org...

Adjective
1. having many parts or sides
(synonym) many-sided
(antonym) bilateral, two-sided
(similar) multipartite

adv. multilaterally, in multilateral way, in a manner that involves many sides

adj. multilateral, having many sides (of an agreement, contract, or discussion, etc.)

adj. multilateral, having many sides (of an agreement, contract, or discussion, etc.); joint