1. A pattern of trade involving three countries, A, B, and C, in which A exports to B, B exports to C, and C exports to A. Provides a nice example of how bilateral trade can be unbalanced even while each country's overall trade balance is zero. 2. Term used specifically for the slave trade, in which ships often traversed one of several triangular routes. For example they might take slaves from Africa to the West Indies, sugar from the West Indies to New England, and rum from New England to Africa.