| Noun | 1. | Triple Frontier - the border area where Argentina and Brazil and Paraguay meet; an active South American center for contraband and drug trafficking and money laundering; a suspected locale for Islamic extremist groupsfrontier - an international boundary or the area (often fortified) immediately inside the boundary Brasil, Brazil, Federative Republic of Brazil - the largest Latin American country and the largest Portuguese speaking country in the world; located in the central and northeastern part of South America; world's leading coffee exporter | |