random breath test
noun [ C ] Australian English uk/ræn.dəm ˈbreθ ˌtest/ us/ræn.dəm ˈbreθ ˌtest/ (abbreviation RBT)
（检测司机是否酒后驾驶的）呼气酒精含量随机检查
a test given by the police to drivers chosen by chance, to measure the amount of alcohol the drivers have in their blood