gold standard

Từ điển Oxford Advanced Learner 8th

ˈgold standard [gold standard] BrE NAmE noun
1. (usually the gold standard)singular an economic system in which the value of money is based on the value of gold
•the ending of the gold standard in 1931
2. usually singular a high level of quality that others try to copy
•Articles like his are the gold standard of news reporting.
•It wasn't just any private jet but one that would become the gold standard.