drop a dime
告密，向警方透露關鍵信息
口語·犯罪或執法語境，表示告密
英文釋義
to make a telephone call, typically to provide information or report someone to the authorities, often anonymously
例句
He dropped a dime on his neighbor for running an illegal business.
典故來源
源自美國公共電話投幣時代，打一次電話需投一枚10美分硬幣，常指匿名向警方告密。