tariff ceiling

基本解释

First, a country has to accept a whole series of agreements. They include a ceiling on tariff can impose on various imported goods and another dealing with the protection of intellectual property.
首先，一个国家必须要接受整套的既定协议和法规，这其中包括政府能够给予各种进口物资设置的关税有固定的上限，另外还有保护知识产权的法规，等等。

The tariff ceiling for agriculture products is expected to drop to 10.8% from 13.2% and for manufactured goods it will go from 9.5% to 7.3% The final bound import rate will be in place on the date of entry into the WTO on most goods, with roughly 25% of future tariff cuts to be implemented three years later.
FORBES: Russian Trade Tariffs Heading Lower In WTO
He proposed to cut top farm tariffs by 60%, put a ceiling of 100% on any single tariff and reduce the average tariff by 46% (the average cut in farm tariffs, a measure preferred by the Americans, was 39%).
ECONOMIST: World trade talks