1. tax on imports or exports, most often calculated as a percent of the price charged for the good by the foreign supplier. The money collected is duty. A tariff may be imposed as a source of revenue for the government. A more common purpose of tariffs is protection against foreign competition. By raising prices of imported goods relative to the prices of domestic goods, tariffs encourage consumers to buy domestic rather than foreign products.

2. schedule of rates or fares in the transportation industry.