1 Term is most frequently used to refer to a customs duty imposed on imported and exported merchandise. See also customs. 2 A public document that enumerates the services offered by a public utility or carrier (freight company), along with the rates charged for those services. Gatt (General Agreement on Tariffs and Trade).The 1977 international agreement, signed by all of the major industrial nations and most other nations of the world, the purpose of which was to promote expansion of trade b...