(military) the beating of a drum as a signal for lowering the flag at sundowna vehement and vociferous advocacy of a cause
"the warmongers kept up their drumbeat on Iraq"
英汉双解大词典
drumbeat/ˈdrʌmˌbiːt/(drumbeats)
1.
N-COUNT（可数名词）
A drumbeat is the sound of a beat on a drum. 击鼓声
2.
N-COUNT（可数名词）
People sometimes describe a series of warnings or continuous pressure on someone to do something as a drumbeat. (一系列的或持续的)警示; 持续的压力 [美国英语] [journalism] [oft N 'of' n]