peter out
phrasal verb with peter verb uk/ˈpiː.tər/ us/ˈpiː.t̬ɚ/
逐渐停止;慢慢消失
to gradually stop or disappear
The fighting which started in the night had petered out by morning. 夜间开始的战斗到早晨逐渐平息了。
The track petered out after a mile or so. 大约一英里后，小路逐渐消失了。