[] () a group of countries that have agreed not to charge taxes (import duties) on goods they trade with each other, and to charge the same taxes on goods imported from other countries 关税同盟（结成关税同盟的国家约定相互间不徵收进口税，对其他国家的进口货物则徵收相同的关税）◆Andorra joined the EC customs union in July 1990. 安道尔於 1990 年 7 月加入欧洲关税同盟。