battering ram
noun [ C ] uk/ˈbæt.ər.ɪŋ ˌræm/ us/ˈbæt̬.ɚ.ɪŋ ˌræm/
（古代战争中攻城时用于捣毁城门的）破城槌；（警察和消防队员用的）破门锤
a long, heavy pole that was used by armies in the past to break down castle doors, etc., now used by police and fire officers to break down house doors