trilateral

Trilateral is an adjective meaning relating to three sides or to three parties; it can also function as a noun referring to a three-party entity or arrangement. The word derives from the Latin tri- meaning three and latus meaning side.

In geometry, three-sided figures are triangles, and the term trilateral is rarely used to describe basic geometric shapes. More often, trilateral describes arrangements or relationships that involve three participants, sides, or components. While the term can appear in technical writing, it is not the standard term for common geometric objects.

In international relations and policy contexts, trilateralism denotes cooperation among three regions, states, or organizations. The most prominent example is the Trilateral Commission, founded in 1973 by Zbigniew Brzezinski, which brings together leaders from North America, Europe, and the Asia-Pacific region to discuss issues of global concern. Beyond this organization, the adjective appears in references to trilateral treaties, dialogues, or cooperative initiatives among three parties, including economic, security, and regulatory contexts.

In business and law, trilateral agreements or negotiations involve three distinct stakeholders, such as three corporations, governments, or agencies. The term is often contrasted with bilateral (two parties) and multilateral (more than two) to describe the scope of cooperation or agreement.

See also: bilateral, multilateral, trilateralism.