From Longman Dictionary of Contemporary Englishfree portˌfree ˈport noun [countable] BBTa port or airport in one country where goods from other countries can be brought in and taken out without being taxed
Examples from the Corpus
free port• The base has been made a free port and special economic zone.From Longman Business Dictionaryfree portˈfree port [countable]COMMERCETRANSPORTTAX a port where CUSTOMS DUTY (=a tax paid on imported goods) does not have to be paid on imports that are to be sent to another country to be sold, or used to manufacture goods that will be sold abroad → port 