drop a dime

Idioms  

1. Inform on or betray someone, as in No one can cheat in this class—someone's bound to drop a dime and tell the teacher. This expression, alluding to the ten-cent coin long used for making a telephone call, originated as underworld slang for phoning the police to inform on a criminal and occasionally is extended to any kind of betrayal. [1960s]

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Example Sentences

They didn’t break the law to make a billion dollars — at least usually not — so you can’t drop a dime on them.

From New York Times • Apr. 7, 2022

That means you might have to pay full price to play God of War: Ragnarok when it releases, while Game Pass subscribers won’t have to drop a dime extra to play Starfield.

From The Verge • Jan. 19, 2022

“To make that reporter drop a dime in the turnstile or risk being locked out from public information is essentially denying yourself access to the truth,” she said.

From Washington Times • Sep. 16, 2015

Embassy in Kabul keeps informants at a distance Locals wanting to drop a dime on terrorists are invited to come to a gate that they can’t reach.

From Washington Post • Jul. 4, 2013

"I'll drop a dime in your hat uncle if you'll stand here and talk to me for a few minutes."

From Slave Narratives: A Folk History of Slavery in the United States From Interviews with Former Slaves: Volume I, Alabama Narratives by United States. Work Projects Administration