1. having three sides
2. involving three parties, groups, or countries

1. a three-sided figure; a triangle

Examples

• The trilateral trade agreement benefited all three nations.
• They formed a trilateral commission to address the border dispute.
• The architect designed a trilateral courtyard for the building.
• The trilateral negotiations lasted several months.
• She drew a trilateral shape on the whiteboard.
• The trilateral summit brought together leaders from three countries.