countdown
noun uk/ˈkaʊnt.daʊn/ us/ˈkaʊnt.daʊn/
[ C ]倒计时
the act of counting backwards to zero
The countdown to the rocket launch will begin at 9.00 a.m. 火箭发射将于上午9点进入倒计时。
[ S ]倒计时阶段
a short period of time leading to an important event
The countdown to the election has already begun. 选举已开始进入倒计时阶段。